KR20140139580A - Method for producing polyamide molded bodies from a polymerizable composition by means of a rotational molding process - Google Patents

Abstract

The present invention relates to a method for producing a polyamide molding body, in which a rotary molding process is carried out on a polymerizable composition containing a lactam.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a polyamide molded body from a polymerizable composition by a rotational molding process,

The present invention relates to a method for producing a polyamide molding by subjecting a lactam-containing polymerizable composition to a rotary molding process.

Once a thermosetting polymer, such as a polyurethane or polyester, is cured, the polymer can not change its shape, unlike a thermoplastic polymer that is reversible in heating, transformation and cooling processes. The most frequently used thermoplastic polymers in the industry include polyamides, as well as polyethylene, polypropylene, polycarbonate, and the like.

Polyamides are presently produced essentially by condensation of dicarboxylic acids or derivatives thereof with diamines or by ring-opening polymerization of lactams. There are also theoretically known methods for preparing polyamides by activated anionic lactam polymerization. For this purpose, lactam such as caprolactam, laurolactam, piperidone, pyrrolidone and the like are polymerized by ring opening in base catalytic anionic polymerization. This is generally achieved at elevated temperatures by polymerizing a melt made of lactam and containing an alkali catalyst and known as an activator (or cocatalyst or initiator).

DE-A 14 20 241 discloses anionic polymerization of lactam using, for example, 1,6-bis (N, N-dibutyl-ureido) hexane as activator in the presence of potassium hydroxide as catalyst do. Activated anionic lactam polymerization using sodium caprolactam is described, for example, in Polyamide, Kunststoff Handbuch [Polyamides, Plastics Handbook], Vol. 3/4, ISBN 3-446-16486-3, 1998, Carl Hanser Verlag, pp. 49 52} and Macromolecules, Vol. 32, No. 23 (1999), p. 7726.

Unpublished EP 11176950.1 and EP 11172731.9 describe solid particles comprising a lactam, a catalyst, and an activator. Such monomer compositions can be used to prepare polyamides by activated anionic polymerization. The particles are prepared by spray drying, if appropriate followed by a grinding procedure where aggregates are formed. Unpublished EP 12151670.9 describes solid particles which, in combination with a lactam component, a catalyst and an activator, can also contain a non-functionalized and / or hydroxy-terminated rubber.

It is noted in the prior art that anionic polymerization of the lactam during molding of the polymer mold may likewise occur in a reactive injection molding process or in a reactive molding process in which a catalyst and optionally other additives are added to the lactam melt during the process. In this type of reactive molding process or reactive injection molding process, the anionic polymerization of the lactam results in enormous technical costs. First, the two-component system must be mixed before use. Additional equipment is needed to make the melt, for example, mixing con- tactors, mixing nozzles, etc., and connecting them to a substantially polymeric mold. If a melt is used, the initiation of some polymerization can not be prevented even before the melt is introduced into the substantially polymeric mold, thus leading to an additional cleaning step of the equipment used.

The preparation of polymer moldings from thermoplastic polymers is known from the prior art. The rotary molding process is a plastic molding process of this type. In this process, the raw material-containing polymer is put into a mold support (rotary molding mold), and the mold support is heated under biaxial rotation. The molten polymer is here homogeneously distributed on the inner wall of the mold support. After cooling, the finished polymer moldings can be separated (Handbook of Thermoplastic Elastomers, Drobny, Jiri George, 2007, 108-121, William Andrew Publishing / Plastics Design Library).

The polymer moldings produced by the rotational molding process can be manufactured in a wide variety of shapes. When compared to the injection molding process, the rotational molding process provides a greater variety of shapes. For example, the shape may be specified to provide for easy incorporation of holes or cutouts in the polymer molding. This is also advantageous when compared with an extrusion process. Rotational molding also permits the production of moldings with low wall thickness variations. However, the crucial advantage of a rotary molding process in comparison with an extrusion process or an injection molding process is the possibility of producing a very cost-effective molding.

Rotational Molding Technology, Crawford, Roy J .; Throne, James L .; 2007; William Andrew Publishing / Plastics Design Library, p. 40] describes the molding of polyamides, specifically polycaprolactam, by a rotational molding process.

US 4,729,862 describes the preparation of thermostable polyamide compositions made of polyamide and copper iodide. The two components are mixed at 282 占 폚. The mixture can then be subjected to a rotary molding process.

The rotational molding process is mainly carried out by introducing a polymer into a mold support and melting it while rotating it to obtain a desired shape. This procedure involves some disadvantages. The mold support must be heated to the melting point of the polymer and, depending on the polymer used, sometimes requires very high temperatures. For example, a temperature of> 200 ° C is generally required for PA6 to be converted to the liquid state. Despite this, the formation of homogeneous melts is not always guaranteed. This results in a significant quality defect in the finished polyamide molding. For example, it is not always possible to prevent the presence of unintended holes in the molding. In addition, processing of PA6 is further complicated by high viscosity and brittleness. In order to obtain a uniformly distributed polymer melt in the rotary molding mold, a sufficient rotation time is required. This can delay the production of the moldings, which is disadvantageous for the economics of the process.

JP 7032390 describes a process for producing ω-lactam in the presence of an anionic polymerization catalyst and an activating agent as a process for molding by rotational molding.

GB 1 133 840 describes a process for molding a lactam while rotating it in a hollow mold. To do this, first provide an activated melt and then transfer it to the mold for polymerization.

IE 991090 describes a rotational molding process, in particular for introducing lactam and activator as premixes into molds.

US 3 780 157 discloses a process for producing a hollow body molded from polyamide through activated anionic polymerization of lactam by a rotational molding process wherein the molding is made by an inorganic filler, The process is described. In column 2, lines 60 to 67, it is mentioned in a very general aspect that a powder mixture comprising a component lactam, a catalyst, and an activator can be introduced into the mold carrier, but in a specific example, the activated lactam melt is first provided, And then transferred to the rotary molding mold in the molten state.

EP 0755966 describes the preparation of a conjugate from reinforcing fibers in a nylon-12 matrix comprising anionically polymerized laurolactam. Again, the activated lactam 12 melt is first prepared in D2 and placed in a liquid state in a hot spinning molding mold. The melt is polymerized by exposure to pressure and temperature. However, it is also disclosed that a mixture of lactam, catalyst, and cocatalyst powders can be used in D2 (page 4, line 37/38).

US 2007/0246475 describes the preparation and use of polymerization compositions comprising polymerization precursors, catalysts, and activators. The mixture can be melted and put into a rotary molding mold in a liquid state, and polymerization and rotational molding processes can be simultaneously carried out. However, the disadvantage here is that not only does the user have to make additional operations, namely the production of the polymer precursor, the catalyst, and the melt from the activator, but also the additional heatable mixing container in addition to the rotary molding system. Separate storage and separate transport of starting materials for the process of producing polyamides by activated anionic lactam polymerization leads to high logistics costs. Similarly, the separate introduction of the raw materials into the process for the production of polyamides by activated anionic lactam polymerization entails high equipment costs.

Additionally, one can not always guarantee stability with respect to polymerization if two melt feeds comprising an activator and the other containing catalyst are to be mixed with each other to provide a polymerizable composition. The melt feed is primarily mixed or blended in-line or in line mixers or mixing nozzles. This forms a more unstable reactive mixture with respect to polymerization, even if it was transferred into a rotary molding mold immediately before. Once the reactive melts have been transferred into the rotary molding mold, additional cleaning of all equipment in contact with the melt should follow, since otherwise the residual melts still present will polymerize to form precipitates and, in the worst case, This can result in occlusion.

Surprisingly, the inventors have discovered that polyamide molding can be produced by a rotational molding process by providing a lactam-containing polymerizable solid composition and simultaneously using it for polymerization and molding. This not only eliminates the above-mentioned disadvantages of the prior art for producing polyamide moldings, but also allows the process to be performed more efficiently in terms of time and energy. The material charged into the mold support or coating the mold support is not a fully polymerized polyamide immediately, but instead is a precursor which can be liquefied at low temperatures, which is advantageous since the in-situ polymerization reaction is carried out thereafter. This method can save not only time but also energy in the process, since the ingredients for making the molding generally have to be heated only once to a temperature higher than the melting point of the monomers.

Another advantage in terms of economics of the process is that the preparation of the polyamide moldings already comprises lactam monomers, catalysts, and activators, and optionally also other additives, and can be added to the mold, for example by increasing the temperature, Polymerizable compositions that can be polymerized directly on a textile support. The polymerizable composition used in the present invention can be put in a solid state in a mold support (rotational molding mold), converted into a liquid that can flow inside, distributed, and polymerized to form a polyamide molding.

The manufacturability of single-component compositions produced directly from the premise of the consumer reduces the high logistics and equipment costs that arise when using processes known from the prior art to produce polyamide moldings. In addition, it becomes possible to produce a marketable form of polymerizable composition and to deliver a stable precursor to the end consumer who makes the molding.

The present invention relates to a method for producing a molding,

(a) A) at least one lactam,

B) one or more catalysts, and

C) at least one activator selected from the reaction products of isocyanates, anhydrides, acyl halides, A) thereof, and mixtures thereof,

Providing a polymerizable composition comprising:

(b) injecting the polymerizable composition provided in step (a) into a solid form which is flowable to a mold support of a rotary molding system,

(c) heating the polymerizable composition in the mold support to a temperature at which the polymerizable composition is a flowable liquid, while rotating, and uniformly distributing the polymerizable composition of the flowable liquid,

(d) polymerizing the polymerizable composition while rotating it,

(e) cooling the polymerized composition, and

(f) separating the polyamide molding from the mold support

/ RTI >

The present invention further provides the use of a polymerizable composition comprising at least components A, B, and C in a rotational molding process to produce a polyamide molding.

A feature of the process of the present invention as opposed to known processes of the prior art is one or more of the following points:

· Efficient use of time

· Efficient energy use

· Lower equipment costs

· High quality polyamide molding

Low residual monomer content.

For the purposes of the present invention, the term "polymerizable composition" means a composition that is solid at room temperature under standard conditions (20 캜, 1013 mbar). The polymerizable composition used in the present invention is also preferably left as a solid at a high temperature. It is preferred that the polymerizable composition used in the present invention is still solid at a temperature of at least 50 占 폚, particularly preferably at least 60 占 폚.

For the purposes of the present invention, the term "mold support" means a rotational molding mold.

For the purposes of the present invention, the term "melt" also refers to a molten lactam with dissolved activator and catalyst. For the purposes of the present invention, the term "melting" is not to be construed as a strict physicochemical meaning, but may also be used as a synonym for conversion into a liquid state that can flow.

For purposes of the present invention, the term "biaxial rotation" refers to rotation about vertical and horizontal axes.

The polymer is "morphologically stable" if it is no longer a flowable liquid.

The preparation of polyamides by activated anionic polymerization is known in principle. A preferred catalyst for anionic polymerization in the process of the present invention is a compound that allows the formation of a lactam anion. The lactam anion can function equally as a catalyst per se.

The polymerizable composition preferably takes the form of particles.

The polymerizable composition is in particular in the form of particles having essentially the same composition, wherein each particle comprises components A), B), and C). For purposes of the present invention, "essentially the same composition" means that the composition of the particles is the same except for deviations that arise from the usual occurrences during the manufacturing process, e.g., the weighing or weighing of the components that form the particles. Each individual particle thus contains all the components necessary for the polymerization reaction. Particles having no clearly the same composition comprise only one of the components A), B) and C), or comprise only two of the components A), B) and C). Accordingly, the polymerizable compositions used in the form of particles in the present invention are fundamentally different from known dry-prepared polymerizable compositions of the prior art (known as dry blends).

The average diameter of the particles is generally from 1 to 2000 mu m, preferably from 10 to 1000 mu m, particularly preferably from 50 to 500 mu m, very particularly preferably from 100 to 200 mu m. Where the average diameter can be determined by light scattering or through the sieve fraction and is the volume average diameter.

It is preferred to use a polymerizable composition comprising from 50 to 99.7 parts by weight, preferably from 70 to 98 parts by weight, particularly preferably from 80 to 95 parts by weight, of at least one lactam A) based on the total weight of the composition.

It is preferred to use a polymerizable composition comprising from 0.2 to 16 parts by weight, preferably from 2.4 to 8 parts by weight, particularly preferably from 3.2 to 5.6 parts by weight, of at least one activator C), based on the total weight of the composition .

It is preferred to use a polymerizable composition comprising from 0.1 to 5.4 parts by weight, preferably from 0.54 to 3.6 parts by weight, particularly preferably from 0.64 to 3 parts by weight, of at least one catalyst B), based on the total weight of the composition.

At room temperature, the polymerizable composition provided in step (a) is stable and solid. In particular, the polymerizable composition used in the present invention is not polymerized below the melting point of the lactam component and is thus stable with respect to any premature polymerization that is not necessary.

The polymerizable composition used in the present invention can be used at any desired time for storage and storage of polyamides for several months.

Particularly suitable lactams are epsilon -caprolactam, 2-piperidone (delta-valerolactam), 2pyrrolidone (gamma -butyrolactam), caprylolactam, enantholactam, laurolactam, and mixtures thereof . Caprolactam, laurolactam, and mixtures thereof are preferred. As the lactam, it is particularly preferable to use caprolactam alone or laurolactam alone.

It is also possible that the polymerizable composition comprises at least one monomer (M) copolymerizable therewith, in addition to at least one lactam. The monomers (M) can in principle be selected from lactones and crosslinking agents. The monomer is preferably selected from lactones. Preferred lactones are, for example,? -Caprolactone and / or? -Butyrolactone. Wherein the amount of the monomer (M) should not exceed 40% by weight based on the total weight of the monomers used in the polymerization reaction. (M) is preferably from 0 to 30% by weight, particularly preferably from 0.1 to 20% by weight, based on the total monomers. The polymerizable composition used in the present invention may comprise crosslinking monomers. The crosslinkable monomer may be a compound comprising at least one group capable of copolymerizing with a lactam monomer. Examples of these types of groups are epoxy, amine, carboxy, anhydride, oxazoline, carbodiimide, urethane, isocyanate, and lactam groups. Examples of suitable crosslinking monomers include, but are not limited to, amino-substituted lactams such as aminocaprolactam, aminopiperidone, aminopyrrolidone, aminocaprolactam, aminoenantholactam, aminolaurolactam, Amino caprolactam, aminopyrrolidone, and mixtures thereof, particularly preferably aminocaprolactam.

In one preferred embodiment of the present invention, the lactam is used alone as a monomer.

Suitable catalysts B) for use in the process of the present invention are those commonly used in commonly used catalysts, such as anionic polymerization.

Catalysts of this type are known, for example, from the literature {Polyamide, Kunststoffhandbuch [Polyamides, Plastics Handbook], 1998, Karl Hanser Verlag}. Catalyst B) is preferably selected from the group consisting of sodium caprolactamate, potassium caprolactamate, magnesium bromide caprolactamate, magnesium chloride caprolactamate, magnesium biscaprolactamate, sodium hydride, sodium, sodium hydroxide, sodium methanolate, Sodium propanolate, sodium butanolate, potassium hydride, potassium, potassium hydroxide, potassium methanolate, potassium ethanolate, potassium propanolate, potassium butanolate, and mixtures thereof.

In particular, catalyst B) selected from sodium hydride, sodium and sodium caprolactamate is used. It is particularly preferred to use catalyst B) selected from sodium caprolactamate. In one particular embodiment, a solution of sodium caprolactamate in caprolactam, such as Brueggolen.RTM. C10 (Brueggemann, Germany), is used in an amount of 17 to 19% by weight of sodium caprolactamate in caprolactam. Likewise a particularly suitable catalyst B) is magnesium bromide caprolactamate, such as Brueggolen.RTM. C1 (Brueggemann, Germany).

The molar ratio of lactam A) to catalyst B may vary widely but is generally from 1: 1 to 10,000: 1, preferably from 5: 1 to 1000: 1, particularly preferably from 1: 1 to 500: to be.

The polymerizable composition used in the present invention comprises at least one activator C) for anionic polymerization.

The term activator also encompasses the precursor of the activated N-substituted lactam of the type which, together with lactam A), forms in situ activated lactam. The number of growth chains depends on the amount of activator. Typically suitable compounds as activator C) are the reaction products of isocyanates, anhydrides, and acyl halides, and their lactam monomers.

Suitable activating agents C) are in particular aliphatic diisocyanates such as butylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, undecamethylene diisocyanate, dodecamethylene diisocyanate, methylene bis (cyclohexyl 4 (Isocyanate), isophorone diisocyanate, aromatic diisocyanate such as tolylene diisocyanate or methylene bis (phenyl 4-isocyanate) or polyisocyanate (e.g., isocyanate from hexamethylene diisocyanate; Basonat HI 100 / BASF SE ), Or allophanates (e.g., ethylalophanate). In particular, a mixture of the mentioned compounds can be used as activator C).

Other suitable activating agents C) are aliphatic diacyl halides such as butylene dionyl chloride, butylenedioyl bromide, hexamethylenedioyl chloride, hexamethylenedioyl bromide, octamethylenedioyl chloride, octamethylenedioyl bromide, Methylenebis (cyclohexyloyl chloride), 4,4'-methylenebis (cyclohexyl oil, cyclohexylmethane, and the like), methylenebearyl chloride, methylenedioyl chloride, decamethylenedioyl bromide, dodecamethylenedioyl chloride, dodecamethylenedioyl bromide, Bromide), isophoronedioyl chloride, isophoronedioyl bromide and also aromatic diacyl halides such as tolylmethylenedioyl chloride, tolylmethylenedioyl bromide, 4,4'-methylenebis (phenyl) acyl chloride, '-Methylene bis (phenyl) acyl bromide. In particular, a mixture of the mentioned compounds can be used as activator C).

As activator C), polymerizable compositions employing at least one compound from the group consisting of aliphatic diisocyanates, aromatic diisocyanates, polyisocyanates, aliphatic diacyl halides, and aromatic diacyl halides are particularly preferred.

One preferred embodiment employs as activator C) at least one compound selected from hexamethylene diisocyanate, isophorone diisocyanate, hexamethylenedioyl bromide, hexamethylenedioyl chloride, and mixtures thereof. It is particularly preferred to use hexamethylene diisocyanate as activator C).

The activator C) can be used in solid form or in the form of a solution. In particular, the activator C) can be used in dissolved form in caprolactam. An example of a suitable activator C) is caprolactam-capped hexamethylene 1,6-diisocyanate. A solution of caprolactam-capped hexamethylene 1,6-diisocyanate in caprolactam is available as Brueggolen C20 (Brueggemann, Germany).

The molar ratio of the lactam A) to the activator C may vary widely, but is generally in the range of 1: 1 to 10,000: 1, preferably 5: 1 to 2000: 1, particularly preferably 20: 1.

The polymeric compositions used in the present invention may also comprise one or more additional components selected from polymers, monomers, fillers and / or fibrous materials, and other additives in addition to the components A), B) and C) described above.

The polymerizable composition may comprise one or more polymers. The polymer may in principle be selected from polymers obtained from the polymerization of the polymerizable composition in this invention, different polymers, and polymer blends. The polymerizable composition used in the present invention comprises at least one polymer in an amount of 0 to 40% by weight, preferably 0 to 20% by weight, particularly preferably 0 to 10% by weight, based on the total weight of the polymerizable composition . When the polymerizable composition comprises one or more polymers, the amount thereof is preferably at least 0.1% by weight, particularly preferably 0.5% by weight, based on the total weight of the polymerizable composition. In certain embodiments, the polymerizable composition does not comprise a polymer formed in the polymerization of the polymerizable composition used in the present invention. In another particular embodiment, the polymerizable composition does not comprise a polymer.

The polymerizable composition may comprise one or more polymers, which are preferably added to the composition in the form of a polymer. In a first embodiment, the added polymer comprises a group suitable for forming a block and / or graft copolymer with a polymer formed from a lactam monomer. Examples of such groups are epoxy, amine, carboxy, anhydride, oxazoline, carbodiimide, urethane, isocyanate, and lactam groups.

In another embodiment, the polymerizable composition is selected from the group consisting of polystyrene, styrene copolymers, polyphenylene oxide ethers, polyolefins, polyesters, polyethers, polyetheramines, polymers derived from vinyl monomers, At least one polymer. In one preferred embodiment, the polymerizable composition is a styrene-acrylonitrile copolymer (SAN), an acrylonitrile-butadiene-styrene copolymer (ABS), a styrene-butadiene copolymer (SB), a polyethylene (HTPE (LTPE), polypropylene, poly-1-butene, polytetrafluoroethylene, polyethylene terephthalate (PET), polyamide, polyethylene glycol (PEG), polypropylene glycol, polyethersulfone (PESU or PES ), One selected from polyvinyl chloride, polyvinylidene chloride, polystyrene, impact-modified polystyrene, polyvinylcarbazole, polyvinyl acetate, polyvinyl alcohol, polyisobutylene, polybutadiene, polysulfone, Or more. This serves, for example, to improve the properties of the product, the compatibility of the components, and the viscosity.

In one embodiment, the polymerizable solid composition comprises one or more fillers. For purposes of the present invention, the term "filler" is broadly interpreted and includes particulate fillers, fibrous materials, and any desirable fulfillment form. The particulate filler can include a wide range of particle sizes, extending from dust to coarse-grained particles. The fillers used may comprise organic or inorganic fillers and / or organic or inorganic fibrous materials. For example, inorganic fillers such as kaolin, chalk, wollastonite, talc powder, calcium carbonate, silicates, titanium dioxide, zinc oxide, graphite, glass particles such as glass beads, nanoscale fillers such as carbon nanotubes It is possible to use carbon black, nanoscale or other phyllosilicates, nanoscale aluminum oxide (Al ₂ O ₃ ), nanoscale titanium dioxide (TiO ₂ ), graphene, and nanoscale silicon dioxide (SiO ₂ ).

In addition, it is possible to use more than one fiber material. It is preferably a known inorganic reinforcing fiber such as boron fiber, glass fiber, carbon fiber, silica fiber, ceramic fiber, and basalt fiber; Organic reinforcing fibers such as aramid fibers, polyester fibers, nylon fibers, polyethylene fibers, and natural fibers such as wood fibers, flax fibers, hemp fibers, and sisal fibers.

It is particularly preferred to use glass fibers, carbon fibers, aramid fibers, boron fibers, metal fibers, or potassium titanate fibers. Concretely, chopped glass fibers are used. The fibers mentioned are preferably used in the form of short fibers in the polymerizable composition. The average fiber length of the short fibers is preferably in the range of 0.1 to 0.4 mm. It is also possible to use a fibrous material in the form of a long fiber or a mixture of a short fiber and a long fiber. However, it is advantageous to use it by adding it directly to the mold support, as will be described in more detail below for laid fiber scrim or fiber braid. Suitable fibers also have an average fiber length in the range of 0.5 to 1 mm, and preferably a long fiber average fiber length of more than 1 mm, and preferably in the range of 1 to 10 mm. In principle, there is no upper limit to the length of a suitable fiber when used directly in a mold support. For example, the length of a fiber in a laid fiber scrim or a fiber braid can be described as infinite.

In particular, it is also possible to use mixtures of the mentioned fillers and / or fibrous materials. As fillers and / or fibers, it is particularly preferred to use glass fibers and / or glass particles, in particular glass beads.

The polymerizable composition used in the present invention preferably comprises from 25 to 90% by weight, especially from 30 to 80% by weight, based on the total weight of the polymerizable composition, of one or more fillers and / or fibrous materials. In certain embodiments, the polymerizable composition used in the present invention comprises from 30 to 50% by weight, based on the total weight of the polymerizable composition, of one or more fillers and / or fibrous materials. In another specific embodiment, the polymerizable composition used in the present invention comprises from 50 to 90% by weight, based on the total weight of the polymerizable composition, of one or more fillers and / or fibrous materials.

In a preferred embodiment, the polymerizable composition may comprise one or more additional additives. The amount of the additive is preferably 0 to 5% by weight, preferably 0 to 4% by weight, particularly preferably 0 to 3.5% by weight, based on the total weight of the polymerizable composition. Examples of additives that can be added are stabilizers such as copper salts, dyes, antistatic agents, release agents, antioxidants, light stabilizers, PVC stabilizers, lubricants, flame retardants, blowing agents, impact modifiers, nucleating agents, and combinations . When the polymerizable composition comprises one or more additives, the amount thereof is preferably at least 0.01% by weight, particularly preferably at least 0.1% by weight, based on the total weight of the polymerizable composition, based on the total weight of the polymerizable composition, Especially 0.5% by weight or more, based on the total weight of the composition.

The polymerizable composition used in the present invention preferably contains, as an additive, an impact modifier. When a polymer compound is used as an impact modifier, it is regarded as a polymer as described above. Specifically, a polydiene polymer (e.g., polybutadiene, polyisoprene) is used as an impact modifier. It preferably contains anhydride groups and / or epoxy groups. The glass transition temperature of the polydiene polymer is in principle lower than 0 占 폚, preferably lower than -10 占 폚, particularly preferably lower than -20 占 폚. The preparation of the polydiene polymer can be based on a polyacrylate, on a polyethylene acrylate and / or on a polydiene copolymer with a polysiloxane, and can be produced by any process that is familiar (e.g., emulsion polymerization, suspension polymerization, solution polymerization, Or vapor phase polymerization) can be used.

The present invention produces a polyamide molding by putting the polymerizable composition in the solid form in a mold support (rotational molding mold) of a rotary molding system, as described above. Suitable rotational molding systems are known in the art.

In a preferred method of producing polyamide molding, the polymerizable composition is introduced into a mold support, as described above, and the support is heated prior to the introduction of the polymerizable composition. Upon introduction of the polymerizable composition used in the present invention, the temperature of the mold support is preferably a high temperature selected according to the lactam used. When caprolactam is used as the lactam component, the temperature of the mold support is preferably 20 to 55 占 폚.

In a preferred method of producing polyamide molding, the oven cavity, which is the location of the mold support and / or mold support, as described above, is sealed after the injection process. It is advantageous to minimize the content of components not specifically involved in the production of the polyamide molding, specifically water, carbon dioxide, and / or oxygen. The components and equipment used should accordingly not contain essentially water, carbon dioxide, and / or oxygen. It is preferred to use an inert gas atmosphere during the storage of the components used and / or during the introduction into the rotary molding apparatus and / or during the polymerization. An example of a suitable inert gas is nitrogen or argon. In many cases, complete inactivation is not necessary, but instead the container, mold, etc. used is blanketed with an inert gas.

The present invention produces a polyamide molding of step (c) by increasing the temperature of the mold support so that the polymerizable composition is a flowable liquid. Wherein the temperature is selected in such a manner as to produce a flowable liquid form of the polymerizable composition and distribute it evenly over the internal area of the mold support. The mold support is heated by methods known to those skilled in the art. This is usually achieved in a gas fuel oven, for example a hot oven.

The polymerizable composition as described above is heated to a temperature which, when subjected to rotation, results in a fluid of sufficient fluidity to be distributed within the mold support. It is usually sufficient to heat it at the melting point of at least the pure lactam component in order to convert the polymerizable composition into a flowable liquid state. In step (c), the heating of the polymerizable composition used in the present invention is carried out at a temperature preferably higher than the melting point of the lactam component used, preferably from 1 to 20 캜, particularly preferably from 3 to 15 캜, particularly from 5 to 10 캜 do. In step (c), the heating of the polymerizable composition used in the present invention is preferably realized at a temperature of less than 180 占 폚, particularly preferably less than 160 占 폚, especially less than 120 占 폚, particularly preferably less than 90 占 폚. The temperature selected in step (c) depends on the choice of the lactam component in the polymerizable composition.

The present invention produces a polyamide molding of step (d) by uniformly distributing the flowable liquid state polymerizable composition over the internal area of the mold support, as described above. The uniform distribution of the flowable liquid composition depends on the viscosity of the polymerizable composition. This is effected, for example, by the lactam component used, the activator, and the catalyst. The uniform distribution of the flowable composition is preferably determined after 1 to 60 minutes, especially after 2 to 30 minutes, especially 3 to 15 minutes.

The conversion of the polymerizable composition used in the present invention into a flowable liquid state is preferably realized by biaxial rotation of the mold support. Likewise, the distribution of the flowable polymerizable composition used in the present invention is preferably realized by biaxial rotation of the mold support.

The present invention converts and distributes the polymerizable composition into a flowable liquid and then produces a polyamide molding of step (d) by polymerizing the polymerizable composition as described above.

The present invention prepares the polyamide molding of step (d) by heating to a temperature above the polymerization temperature and polymerizing the polymerizable composition as described above. The temperature here depends on the process parameters. The temperature is preferably in the range of 50 to 200 占 폚. It is particularly preferable that the temperature is in the range of 60 to 170 占 폚. In particular, the temperature for using caprolactam as the lactam component is in the range of 85-150 < 0 > C.

The polymerization of step (d) is preferably carried out by increasing the temperature of the mold support by biaxial rotation.

In one embodiment, the polyamide molding is prepared by polymerizing the polymerizable composition and using an extended residence time of the polymerizable composition of a liquid that is flowable in the mold support, as described above.

The polymerization time of the polymerizable composition used in the present invention depends on the temperature and the nature and concentration of the catalyst and activator. The polymerization of the polymerizable composition in step (d) of the process of the present invention is generally completed after 1 to 60 minutes, preferably 2 to 30 minutes. In the process of the present invention, the polymerization time is defined as the time when the oven temperature has started to reach the selected polymerization temperature (final temperature) and ends when cooling has started (= step (e)).

The conversion of the liquid to a liquid, the distribution procedure, and the rotational speed of the mold support during the polymerization reaction depend on the viscosity of the polymerizable composition. The rotation speed of the shaft is generally in the range of 1 to 40 rpm (revolutions per minute), preferably in the range of 1 to 20 rpm.

It is generally advantageous to minimize contamination, such as water, carbon dioxide and oxygen, which can lead to termination of the anionic polymerization reaction. Therefore, all components used should, in principle, be dry and free of oxygen and carbon dioxide. It is preferred that the polymerization reaction is carried out with substantially no oxygen, carbon dioxide, and water. In particular, the steps of the process of the present invention are carried out with substantially no oxygen, carbon dioxide, and water.

It is preferred that the conversion into a flowable liquid, the distribution of the flowable polymerizable composition, and the presence of an inert gas atmosphere in the mold support during the polymerization reaction. In particular, an inert gas atmosphere is present during the polymerization reaction. (A), (b), (c), (d) of the process of the present invention in the presence of a sufficient amount of an inert gas, , And / or (e), or all of the above steps.

The polymerization reaction by rotation in step (d) leads to cooling (= step (e)) of the polymerized composition produced in the present invention. To this end, the molding generally cools the polymerized composition to a morphologically stable temperature. The mold support is cooled in step (e) to a temperature of preferably 20 to 80 캜, particularly preferably 30 to 70 캜, particularly preferably 50 to 70 캜.

The cooling is preferably carried out by biaxial rotation of the mold support. For cooling, it is desirable to separate the mold support from the oven cavity. Cooling of the mold support is preferably accomplished by contact with a coolant, such as air or an air / water mixture, or simply by opening the mold support. The cooling phase depends on the wall thickness of the polyamide molding produced.

The cooling process is terminated when the polyamide molding is morphologically stable. Which can then be separated from the mold support.

The present invention also provides a method of making a polyamide molding as described above, wherein the mold support comprises one or more fillers and / or fibrous materials.

In one preferred embodiment, the mold support comprises woven fibers and / or fiber rims, such as glass fiber mats and / or glass fiber rubbers.

In addition, the filler and / or fiber material can be put into the mold support together with the polymerizable composition. Optionally, the filler and / or fiber material added may be selected from the fillers and / or fibers mentioned above.

The process of the present invention can be used to produce polyamide moldings having a high content of fillers and / or fibrous materials. In particular, the content of filler and / or fiber material in the polyamide molding obtained by the process of the present invention is in the range of from 30 to 90% by weight, in particular from 30 to 80% by weight, 50% by weight. In certain embodiments, the content of filler and / or fibrous material in the polyamide molding is from 50 to 90% by weight, based on the total weight of the polymerizable composition.

The polyamide moldings produced by the process of the present invention can be used in particular as automotive body parts, such as passenger compartment or wheel surround, or as automotive parts, such as frame cladding or dashboard manufacturing materials, and interior materials for passenger compartments. Other possible applications for polyamide molding are as tanks, gear wheels, housings, packaging films, and as the inlayers of coatings.

In principle, the polyamide moldings produced by the process of the present invention are suitable for use in small electronic devices such as cell phones, laptops, iPads, or any housing for general plastic articles imitating metals.

The process of the present invention for preparing polyamide moldings by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is characterized by a number of advantages compared to the use of melt or polymer powders .

The process of the present invention for preparing polyamide moldings by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is advantageous in terms of logistical advantages such as ease of raw material storage, One raw material transport, and an easy raw material introduction into the process.

In addition, the process of the present invention for producing polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is advantageous because the polymerizable composition has a low melting point and is therefore required And the amount of energy and time is less than when the polymer powder is used.

In addition, the process of the present invention for producing polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is advantageous because the polymerizable composition of the flowable liquid has a low viscosity, Characterized by the advantage that it exhibits a better flow pattern when compared to the polymer powder, obviously in a better, more homogeneous, faster distribution of the polymerizable composition of the flowable liquid in the mold support.

In addition, the process of the present invention for producing polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is characterized by the advantage that the polymer is produced in situ. Accordingly, the coagulation of the polyamide molding is, specifically, actually faster than that of the polymer powder at a temperature lower than the melting point of the polyamide.

In addition, the process of the present invention for producing a polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is advantageous in that the solid state polymerizable composition is added to a mold support (rotational molding mold) And is characterized by the advantage that in the mold, it can be converted into a flowable liquid, distributed and polymerized to obtain polyamide molding.

In addition, the process of the present invention for producing polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is advantageous in that the rotational molding process is reduced to a heating phase The conversion to a flowable liquid and the distribution of the polymerizable composition) and, advantageously, the cooling phase.

The process of the present invention for producing polyamide molding by anionic lactam polymerization activated by a rotational molding process using a polymerizable composition as a raw material is characterized by high efficiency in terms of energy and time.

The following examples provide further explanations of the present invention. The present embodiments illustrate some aspects of the present invention, but should not be construed as limiting the scope of protection of the present invention.

Manufacture of 150 L container for liquid:

The inactivated mold support was preheated to a temperature T _mold . The fine powder polymerizable composition A was introduced into the mold support by an inert solid valve. At the oven temperature of T _{oven, 1} , the mold support was rotated for a time t ₁ at a rate of rotation x around the major axis and at a rate of turn y about the second axis. The oven temperature was raised to T _{oven, 2} . Upon reaching T _{oven, 2} , during the heating procedure and after the target temperature, the rotation of the mold support was continued in the same manner for a time t ₂ . Once the supply of energy to the oven was stopped, the mold support was cooled by method B and opened after time t ₃ . The finished container for liquid was separated.

Claims (14)

As a method for producing polyamide molding,
(a) A) at least one lactam,
B) one or more catalysts, and
C) at least one activator selected from the reaction products of isocyanates, anhydrides, acyl halides, A) thereof, and mixtures thereof,
Providing a polymerizable composition comprising:
(b) injecting the polymerizable composition provided in step (a) into a solid form which is flowable to a mold support of a rotary molding system,
(c) heating the polymerizable composition in the mold support to a temperature at which the polymerizable composition is a flowable liquid, while rotating, and uniformly distributing the polymerizable composition of the flowable liquid,
(d) polymerizing the polymerizable composition while rotating it,
(e) cooling the polymerized composition, and
(f) separating the polyamide molding from the mold support
≪ / RTI > The method of claim 1, wherein the polymerizable composition takes the form of particles and all of the particles have substantially the same composition, wherein each particle comprises components A), B), and C). The process according to any one of claims 1 to 5, wherein the temperature of the mold support when the polymerizable composition is introduced in step (b) is 20 to 55 占 폚. The process according to any one of claims 1 to 3, wherein the polymerizable composition in step (c) is added at a temperature of 1 to 20 占 폚, preferably 3 to 15 占 폚, more preferably 5 to 20 占 폚, RTI ID = 0.0 > 10 C. < / RTI > 5. The process according to claim 4, wherein step (c) is completed after 1 to 60 minutes, preferably 2 to 30 minutes, particularly preferably 3 to 15 minutes. 6. The process according to any one of claims 1 to 5, wherein in step (d) the polymerizable composition is heated to a temperature higher than the melting point of the lactam used by 10 to 100 DEG C, preferably 30 to 80 DEG C Way. 7. The method of claim 6, wherein step (d) is completed after 1 to 60 minutes, preferably 2 to 30 minutes. The process according to any one of claims 1 to 7, wherein in step (e) the mold support is cooled to a temperature of from 20 to 80 캜, preferably from 30 to 70 캜, particularly preferably from 50 to 70 캜 / RTI > 9. The composition according to any one of claims 1 to 8, wherein the polymerizable composition comprises, based on the total weight of the composition,
50 to 99.7 parts by weight of at least one lactam A),
0.1 to 3.6 parts by weight of at least one catalyst B), and
0.2 to 8.0 parts by weight of at least one activator C)
≪ / RTI > 10. The composition according to any one of claims 1 to 9, wherein the polymerizable composition is selected from the group consisting of? -Caprolactam, 2-piperidone, 2-pyrrolidone, caprylolactam, enantholactam, laurolactam, At least one lactam A selected from the mixture). 11. The composition of any one of claims 1 to 10 wherein the polymerizable composition is selected from the group consisting of sodium caprolactamate, potassium caprolactamate, magnesium bromide caprolactamate, magnesium chloride caprolactamate, magnesium biscaprolactamate, sodium hydride Sodium hydroxide, sodium hydroxide, sodium methanolate, sodium ethanolate, sodium propanolate, sodium butanolate, potassium hydride, potassium, potassium hydroxide, potassium methanolate, potassium ethanolate, potassium propanolate, potassium butanolate , And mixtures thereof). ≪ / RTI > 12. The process of any one of claims 1 to 11, wherein the polymerizable composition comprises one or more activations selected from hexamethylene diisocyanate, isophorone diisocyanate, hexamethylenedioyl bromide, hexamethylenedioyl chloride, (C). ≪ / RTI > 13. A process according to any one of claims 1 to 12, wherein the polymerizable composition has a viscosity of 1 to 2000 m, preferably 10 to 1000 m, particularly preferably 50 to 500 m, very particularly preferably 100 to 200 m Lt; RTI ID = 0.0 > a < / RTI > range of mean diameters. Use of a polymerizable composition comprising components A), B) and C) as defined in any one of claims 1 to 13 for producing polyamide molding by a rotational molding process.