DE2828437A1 - MOLDED BODY WITH A RUSH-LIKE STRUCTURE AND PROCESS FOR THE PRODUCTION THEREOF - Google Patents

Description

The invention relates to a rush-like shaped body made of an acrylic polymer, its outer skin structure and The internal structure is very similar to that of the natural rush and its internal water absorption capacity Is 5 to 200%, and it also relates to a method for producing such a shaped body.

In Japan, tatami surface sheets, floor coverings in the form of sheets and strips as well as decorative mats provided with patterns of various types, mainly are made up of the rush plant (of the genus Juncus), have been used habitually since ancient times, however, their production has gradually declined in recent years. This is due to, that on the one hand it is becoming increasingly difficult to cultivate good quality rush plants because of the associated air pollution in the area of cultivation areas of the bulrush, which is increasing more and more Develop in industrial areas and, on the other hand, it is difficult to bring in enough manpower to live in Much labor must be invested in the cultivation of the rush.

There has therefore been no lack of attempts to find substitution products for the natural rush from synthetic ones To create plastics that are manufactured on an industrial scale and of consistent quality. So were E.g. already floor panels and floor mats that are woven from hollow or foamed linear products made of polypropylene, polyethylene, polyvinyl chloride and the like on a laboratory and experimental scale or already offered on the market. Into the-

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special synthetic rush products based on Polypropylene spread rapidly because of them Cheapness, firmness and beauty. Such synthetic cane moldings and their production from synthetic Plastics is described in numerous publications, e.g. in the JA patent publication 3477/1970 (products based on foamed polyethylene), JA patent publication 4033/1975 (products based on polypropylene-polyvinyl alcohol), JA utility model publication 27341/1970 (polyolefin based products) and JA patent publication 23905/1972 (products based on foamed polyvinyl alcohol and foamed polyvinyl chloride).

Although synthetic plastics based on polypropylene, polyethylene, polyvinyl chloride and poly- vinyl alcohol has the advantage of being cheap and mass produced must be viewed as disadvantageous that they do not result in synthetic rush products, which are superior to the natural rush in appearance and practical functionality. For example, the Synthetic lentil products do not have the advantages of the vegetable rush, e.g. sufficient moisture absorption capacity (Water absorption capacity) elastic resilience, dimensional stability and Refreshment feeling and they have not yet surpassed the natural rush in their beneficial applicability.

However, there are also those made of natural rush Tatami surface sheets and floor panels are not completely free from disadvantages in terms of their functionality and they leave in practical use left to be desired in various respects. So stays

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not hidden from the user that they are not entirely satisfactory, particularly with regard to light stability, dyeability, uniformity of quality and _waste: abrasion resistance.

It can thus be seen that the tatami products, which have become an indispensable part of Japanese life, still present various problems when using tatami products Made from natural or synthetic rush, there is still a lot that needs to be improved.

The object of the invention is to eliminate the disadvantages of known products and a synthetic one To create a rush-like shaped body that resembles that of natural rush, a massive water absorption capacity possesses and can be used for tatami products in a particularly advantageous manner.

The invention is based on the knowledge that the specified object by creating a synthetic Foam from an acrylic! Polymer is detachable, which aic material for tatami surface sheets, floor mats, Patterned wall and floor coverings and the like are particularly advantageously suitable for a massive elastic resilience and the imparting of a feeling of refreshment are characterized and excellent properties in terms of light stability, dyeability, uniformity of quality, abrasion resistance, water absorption capacity and moisture absorption capacity having.

The rush-like shaped body according to the invention is thereby characterized in that it is constructed from an acrylic polymer made of acrylonitrile alone or of acrylic

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nitrile and at least one ethylenically unsaturated Compound is obtained and has a foamed structure and an internal water absorption capacity has from 5 to 200%.

The synthetic rush-like shaped body according to the invention has a pronounced foamed structure similar to that of the rush plant, with the surface layer is in the form of a wrinkled and wrinkled structure and the inner layer has a foamed structure. The synthetic cane material of the present invention can therefore impart a feeling of refreshment similar to that of tatami covering material made from the natural rush plant. Furthermore, the inventive Molded body due to the high wettability of the acrylic poly- meren have a massive water absorption capacity and moisture absorption capacity. The shaped body according to the invention is also distinguished by excellent properties regarding elastic resilience or elastic hollowing as well as dimensional stability and it also has improved evenness in quality and gloss.

Due to the composition of the starting material (acrylic polymer) used, the artificial Rush moldings have a markedly improved light stability and colorability, thereby being commercial value is increased even further.

In addition to its light weight and ease of handling, the synthetic of the present invention has rush-like ones Moldings also have the advantage that they can be made with the help of conventional, known tatami surface web weaving machines

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can be easily woven.

Due to the combined effect of the composition of the starting material, pronounced rush-like appearance and characteristic water absorption property met the synthetic rush-like shaped body according to the invention has various emotional and practical functions, those in well-known artificial rush materials made from synthetic plastics and even in natural ones Rush products cannot be found. This must be seen as a very important advantage from the industrial and social point of view.

These numerous advantages are due, among other things, to that the foamed molded body according to the invention is very similar to the natural cane material. The actual appearance of the foamed of the present invention Shaped body is illustrated in more detail by the accompanying drawing, which is made with the scanning electron microscope taken photographic recordings, shows which represent:

Figures 1 (a) and 1 (b) are electron micrographs

a cross-section or a side view in the longitudinal direction of a rush plant,

Figures 2 (a) and 2 (b) are electron micrographs

a cross-section or a side view in the longitudinal direction of a synthetic Molded body obtained from a known polypropylene linear product, and

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Figures 3 (a) and 3 (b) are electron micrographs

a cross-section or a side view in the longitudinal direction of an inventive rush-like shaped body.

All pictures were taken at 50x magnification.

It is easy to see from the figures that the inventive rush-like moldings, although it is a synthetic product, have a distinctive appearance like natural rush with a wrinkled structure on the surface and a foamed structure on the inside. It can also be seen that the polypropylene molded body, which is a known product, does not have such a pronounced rush-like appearance. For the production of these microscopic photographs, a scanning electron microscope JSM-U3 made by Japan Electron Optics was used Laboratory Co., Ltd. used.

An important feature of the synthetic according to the invention rush-like shaped body ^ can be seen in the fact that he has a special internal water absorption capacity. Namely, when the molded body has an internal water absorption capacity in the range from 5 to 200%, preferably from 30 to 180%, measured by the method given below, its structure is to be considered acceptable and appropriate. With an internal water absorption capacity of less than 5%, the end product is conveyed in the form of tatami surface strips, floor and wall coverings and like a sticky feeling like that of cane materials made from common polypropylene and cannot convey that refreshing dry feeling as occurs in tatami products made from natural rushes, on the other hand, the internal water

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absorption capacity 200%, so is the practical strength and in particular, the resistance to abrasion is seriously lowered.

The stated internal water absorption capacity was determined by the following method.

Samples of the synthetic rush-like shaped body taken at random are cut into pieces 10 cm in length and dried to absolute dryness to produce the material to be measured, which is then weighed precisely (W ₀ (g)). The test piece is immersed in water at room temperature for 1 hour. After 1 hour, it is removed from the water and wrapped in a piece of gauze. It is then placed in a centrifuge and centrifuged for 2 minutes at 1600 g to remove the excess water from the test specimen, whereupon it is precisely weighed (W ₁ (g)). The internal water absorption capacity is then calculated using the following formula:

W ₁ - W ₀

Internal water absorption capacity (%) = χ

^W 0

It deserves to be emphasized that in order to carry out this measurement the internal water absorption capacity is determined under severe centrifuge conditions. Under such conditions, practically all of the free water present in the molded body is removed and only the amount of bound water that is coordinated with the nitrile groups of the acrylic polymer and / or the amount of water that remains in the fine foam structure is specified as the specified Water content (W- - Wq) indicated. This water content (W ₁ - W “) is closely related to the advantageous one

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Feature that the final product obtained does not have a sticky feeling. It should be emphasized, however, that this water content is completely different in nature from that water content that is measured according to the usual water determination method. It goes without saying that the water content (W ₁ W _n ) is not an amount of water that always remains in the molded body and can therefore be removed by suitable drying methods, whereby the molded body can have a feeling of dryness.

An example of the water absorption capacity of natural rush measured by the specified method, a synthetic rush product according to the present invention and a known rush product on the The basis of polypropylene is given in the following list:

Internal water absorption capacity (%)

Natural bulrush 90.5

moldings according to the invention 73.5 polypropylene product below 0.1

The results show that the rush-like according to the invention Shaped body is also very similar in terms of internal water absorption capacity of the rush plant.

In relation to the stated water absorption capacity, the following important factor should also be emphasized. If the immersion time of the test object to be measured in the water is limited to 2 minutes in the specified measuring method for determining the internal water absorption capacity (in the method described above it was 1 hour), the internal water absorption capacity reaches 10 to 6 0 %, preferred

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wise 20 to 50%. This fact is interesting in that it changes the water absorption behavior with the expiration of the Time shows and it can be seen that e.g. a certain Amount of water in contact with a mat produced from the synthetic molding according to the invention is absorbed much faster than a known polypropylene product and practically as quickly like a product made from natural rush.

A comparison of the internal water absorption capacity after immersion in the water for 2 minutes is shown in the following list:

Internal water absorption capacity (%) after immersion for 2 minutes

Natural rush 30.0

Molded body according to the invention 31.0

Polypropylene product below 0.1

The molded body according to the invention with excellent properties both in terms of the conveyed feeling and the practical functions, which is ideally suited as a material for tatami surface sheets and floor coverings, owes its pronounced advantageous effects to the use of an acrylic polymer as the starting material, its foamed structure and its unusual water absorption behavior. The advantages and effects of the molding according to the invention become even more pronounced when the specified features are present and an average diameter of 0.5 to 5 mm, preferably 0.8 to 4 mm and in particular 1 to 2.5 mm, and a bulk density (which to be defined below) from 0.05 to 0.8 g / cm ³ , preferably from 0.1 to 0.5 g / cm ³ . Namely, if the diameter is less than 0.5 mm or

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larger than 5 mm, such a shaped body is not very suitable for use as tatami surface webs. Further, if the bulk density or bulk density is less than 0.05γ, the elastic resilience and practical strength are insufficient (or the flexural rigidity is insufficient), so that weaving (manufacture of tatami surface sheets) becomes difficult. If the bulk density is over 0 _r 8, it becomes difficult to give a feeling of refreshment as in the case of the natural rush, and the commercial value of the product is markedly decreased.

In the following the process for the preparation of the inventive Molded body consisting of an acrylic polymer and its surface layer and / or foamed Inner layer are equal to that of the natural rush and its inner water absorption capacity 5 to 200%, will be explained in more detail.

To produce the synthetic according to the invention For a rush-like shaped body, it is important as a starting material To use a-Aery! polymer, which is obtained from acrylonitrile alone or acrylonitrile and at least: one ethylenically unsaturated compound. Such a polymer is then converted into a molded body with the desired surface and internal shape transferred by dry spinning, mass spinning, Spin it in melt or spin it in melt ... With these Spinning processes can: the rush-like: foamed linear structure are obtained by (1) in. the Polymer solution or "polymer melt, a (organic or inorganic) heat expansion agent! introduces, (2); in the polymer solution or -melt a volatile .liquid: a-r leads, (3) in the polymer solution or melt air, carbon

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blowing acid gas or nitrogen gas, or (4) a Polymer solution or melt produced at high temperature and high pressure in a zone with lower Pressure extruded (injected).

If possible, such a foamed product produce whose surface layer forms a wrinkled and wrinkled structure and whose inner layer forms a foamed structure of the specified type and which has a water absorption capacity within that specified Has area, one is not limited to a particular manufacturing method.

According to a first preferred embodiment, an acrylonitrile polymer composition obtained by uniformly mixing 30 to 90 wt and 2 to 63% by weight of acrylonitrile under a pressure equal to or greater than the autogenous pressure that is established, hot melted, whereupon the pressure of the system in which the melt obtained is present is increased to 0.5 to 15 bar (0 , 5 to 15 kg / cm ² ) and the melt is extruded through a nozzle into a zone in which atmospheric pressure prevails, with a foamed structure being obtained.

According to a second preferred embodiment for carrying out the process according to the invention, an acrylonitrile polymer composition, obtained by uniformly blending from 30 to 90% by weight of the above Acrylic polymers and 70 to 10% by weight of water, under a pressure equal to the autogenous pressure that is established

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Pressure or greater than this is melted hot, whereupon the pressure of the system in which the melt obtained is present is reduced to 0.5 to 15 bar (0.5 to 15 kg / cm ² ) and the melt passes through a nozzle into a Atmospheric pressure zone is extruded to form a foamed structure.

According to a third preferred embodiment for carrying out the process according to the invention, acrylonitrile alone or a monomer mixture of acrylonitrile and at least one ethylenically unsaturated compound in a system, the water in an amount of 10 to 30 wt .-%, based on the total weight of water and monomer (s), polymerized under a pressure above the vapor pressure generated in the polymerization system at a temperature above 120 ^° C., whereupon the pressure is reduced to 0.5 to 15 bar (0.5 to 15 kg / cm ² ) below Formation of an acrylonitrile polymer composition which is practically in a molten state, and the resulting acrylonitrile polymer composition is extruded through a nozzle into a zone of atmospheric pressure to form a foamed structure.

With the help of these methods, the advantageous production succeeds of the synthetic cane-like shaped body according to the invention, the surface layer of which is in Form. Is formed by wrinkles and folds extending in the longitudinal direction, and the interior of which is a Forms a foamed structure, the shaped body having a special water absorption capacity in the desired range having.

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Although the specified embodiments for the production of the rush-like shaped body according to the invention prove to be advantageous, a suitable selection of parameters of the specified embodiments is of course possible, for example with regard to the degree of printer reduction, the diameter of the nozzle, the amount of acrylic polymer used and the like, whereby the achievement of an average diameter of 0.5 to 5 mm of the foamed molding and a bulk density (which will be defined in more detail below) of 0.05 to 0.8 g / cm ^{3 is} made possible, which the advantages achievable according to the invention increases even further.

Furthermore, the internal water absorption capacity and the foaming state of the synthetic according to the invention rush-like molded body also by appropriately changing the parameters of the means of production within of the permissible range varies and is selected accordingly with regard to the intended use will.

Ai'hjserdem is a regulation and control of the water absorption capacity of the molding according to the invention also possible in other ways, e.g. in that the surface of the foamed molding is covered with a Resin film is coated, reducing the diameter and number of fine, moving from the inside to the surface of the foamed molded body extending openings can be modified.

The term "Acry! Polymer" used serves as a collective term for polymers that are composed of acrylonitrile alone or in combination with at least 40% by weight, preferably at least 60% by weight of acrylonitrile

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an ethylenically unsaturated compound which can be polymerized via radicals and which makes up the remainder. Typical ethylenically unsaturated compounds which can be used according to the invention are, for example, vinyl halides or Vinylidene halides such as vinyl chloride, vinyl bromide, vinyl fluoride and vinylidene chloride; unsaturated carboxylic acids, e.g., acrylic acid, methacrylic acid, maleic acid, and itaconic acid, and salts thereof; Acrylic acid esters, e.g. methyl acrylate, Ethyl acrylate, butyl acrylate, octyl acrylate, methoxyethyl acrylate, Phenyl acrylate and cyclohexyl acrylate; Methacrylic acid esters, e.g. butyl methacrylate, octyl methacrylate, methoxyethyl methacrylate, Phenyl methacrylate and cyclohexyl methacrylate; Methyl vinyl ketone; Vinyl ester, e.g. vinyl formate, Vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; Vinyl ethers, e.g., methyl vinyl ether and ethyl vinyl ether; Acrylamide and its alkyl substitution products; unsaturated sulfonic acids such as vinyl sulfonic acid and p-styrene sulfonic acid and their salts; Styrene and its alkyl or halogen substitution products such as CÄ - methylstyrene and Chlorostyrene; Allyl alcohol and its esters or ethers; basic vinyl compounds, e.g. vinyl pyridine, vinyl imidazole and dimethylaminoethyl methacrylate; and vinyl compounds such as acrolein, methacrolein, vinylidenecyanide, Glycidyl methacrylate and methacrylonitrile. This Ethylenic unsaturated compounds can be used alone or in combination with one another.

According to a further embodiment of the invention can Part or all of the surface layer or the inner layer of the synthetic rush-like according to the present invention Molded body incorporated conventional known additives by coating, dipping and the like methods v / earth, e.g. modifiers such as anti-discoloration agents, Stabilizers against heat, fire retardants, softeners

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makers, antistatic agents, fragrances, pigments, antifungal agents, Lubricants, anti-pollution agents, stabilizers against ultraviolet rays, dyes, Deodorants, matting agents and the like. The number and type of modifiers that can be used is so large that only some of these compounds are given here, the invention of course not is limited to these examples.

Pigments which can be used according to the invention are, for example, white lead, Zinc white, ultramarine, benzidine orange, benzidine yellow, copper phthalocyanine green, pearl pigment, permanent white and like; suitable antistatic agents are e.g. polyoxyethylene, acrylamine, alkylphenol / ethylene oxide addition products, Stearic acid monoglyceride, sorbitan distearate, trimethyloctadecyl ammonium chloride and the like; suitable Plasticizers are e.g. octadecylamine acetate, octadecylethylene urea, Trimethyldodecyl ammonium chloride, sorbitan monolaurate and the like; suitable flame retardant Agents are e.g. tetrabromobisphenol, tetrabromobutane, tetrabromophthalic anhydride, perchloropentacyclodecane, Barium metaborate, methyl hydrogen phosphate, the most halogen-containing organic compounds and the like; suitable antifungal agents are e.g. tributyltin acetate, Zinc dimethyl dithiocarbamate, salicylanilide, phenyl mercury acetate, bis (trimethyl tin) oxide and the like.

The synthetic, rush-like, according to the invention from such an acrylic polymer obtained molded body with the specified special foam structure, i.e. with a wrinkled and wrinkled surface and a foamed inner part, and with an internal water absorption capacity within the specified range in addition to the

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specified suitable diameter and bulk density or the / bulk density in the specified range, dissolves completely the identified problems and disadvantages of the known synthetic rush-like linear products adhere and which themselves are the natural rush plant shows. The synthetic rush-like shaped body according to the invention is therefore suitable for a wide range of applications e.g. for high-quality tatami surface strips, floor coverings and mats, patterned walls and floor mats, decorative materials and the like. It should be particularly emphasized that the inventive Shaped body gives a feeling of refreshment or coolness, especially in times of high and high temperatures Humidity as it is typical for the summer in Japan.

The following examples are intended to explain the invention in more detail without restricting them. In the examples, all parts and percentages are by weight, if nothing other is indicated.

The bulk density (volume or mass density) given in the examples was determined by the following method.

Definition of bulk density.

The bulk density (D) is defined by the following formula:

D = "W / / (S") χ NV (g / cm ³ )

where W '(g) is the weight of the molding, N (cm) is the length of the molding, S (cm ² ) is the apparent cross section of the molding.

The specified cross-section £ T is defined as follows:

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(di) ² YI n (cm ² )

where di (cm) is the apparent diameter of the molded article means, the measurements i-fold (i = 1 '- ^' n) in the longitudinal direction repeated at randomly chosen intervals.

Calculation of the bulk density.

The bulk density was as follows according to the above formula certainly:

A length 100 cm length of the rush-like shaped body to be measured was prepared. The apparent diameters (d) at both ends of the test piece and at 9 measuring points, which were selected in the longitudinal direction at a distance of 10 cm, were measured twice at different measuring points with a pair of feeler gauges or a micrometer, the second measurement after rotating the
Test specimen carried out by 90 ° in the circumferential direction
became.

For each measured value obtained (di; i = 1 '-> ^ 22) the mean value of the corresponding cross-section -f ^ "(-τ-), ie the apparent cross-section [S) was calculated according to the following formula (with each cross-section in the 11 Measuring points was assumed as a circle):

(di) ² / / 22 (cm ² )
i = 1 J

The weight (W) of the test piece (100 cm in length) was determined, and the bulk density (D) was then found from following formula:

D = W / ^ (S) χ 100 ^ (g / cm ³ )

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The larger the value of D, the larger it goes without saying the bulk weight.

example 1

An acrylonitrile polymer composition was prepared by mixing 60 parts of a 90% acrylonitrile and 10% methyl acrylate acrylonitrile polymer, 12 parts of a 5% solution of sodium bicarbonate, and 28 parts of acrylonitrile. The polymer mass was introduced into a customary known melt spinning machine, in which it was heated at 140 ^° C. under autogenous pressure
was melted.

The melt obtained was then in a zone of
Atmospheric pressure extruded through a nozzle of 1.3 mm diameter and the resulting extrudate was 1.2 times in the longitudinal direction in dry heat at 120 ⁰ C
stretched, with a synthetic rush-like
Shaped body was obtained, which was the final product.

The obtained synthetic molded article had a wrinkled structure in the surface layer and that
Inside showed a good foamed state. In
Table I below shows the apparent cross-section (S) and the bulk density (D) of the process product obtained and, for comparison, the corresponding values of the natural rush.

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Table I.

apparent cross section bulk density (cm ² ) (g / cm ³ )

product according to the invention 1.47x10 0.23

Natural product 1.78 χ 10 ~ ² 0.20

The results show that the synthetic molded body according to the invention of the natural rush plant very much strongly resembles.

The synthetic molded body obtained was then placed in a tatami web loom and in a tatami surface web processed which was light in weight and excellent in moisture absorption capacity, water absorption capacity, Had dyeability and light stability, and had very high commercial value. An abrasion test, that with a tatami product made from natural rush and with one made from synthetic according to the invention Shaped body was carried out, showed that the latter had a very excellent abrasion resistance.

Example 2

Four types of acrylonitrile polymer compositions were prepared by mixing an acrylic polymer consisting of 60% acrylonitrile and 40% vinylidene chloride and water in the proportions shown in Table II. Each of the polymer compositions obtained was introduced into a melt spinning machine, in which the mass was melted at 16O ⁰ C under autogenous pressure. The melt was then extruded into a zone of atmospheric pressure through a single nozzle having a diameter of 1.2 mm. The extrudate obtained was

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then to 1.1 times stretched at 100 ⁰ C in the longitudinal direction in a humid atmosphere. The obtained product was then dried to obtain four types of synthetic rush-like molded articles which were the final products.

The appearance and bulk density of the four types of synthetic molded articles are also shown in Table II listed.

From the results in Table II it can be seen that the synthetic rush-like products with a The bulk density within the specified range represents a material that has the same appearance and feel made from a natural rush product and that there was no difficulty in weaving. In this context it deserves to be emphasized that a synthetic tatami material consists of a common one known polypropylene linear product with a bulk density of 0.3 in terms of sensory properties as well was tested and found to be inferior in terms of appearance, moisture and water absorption capacity proved, quite apart from that, that it did not want to convey any feeling of refreshment.

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Table II

20th

Starting acrylonitrile polymer composition

Acrylic polymer water

80

CD OO OO CaJ

65

Properties of the synthetic molded article

10

structure

Surface: wrinkled. Inside: foamed

dto.

Bulk density (g / cm ³ )

35

dto.

70

30th

dto.

Behavior of the tatami surface covering

Weaving processability

problem-free

Appearance and grip

very similar in appearance and feel to natural rush products

similar to the naturally easily borrowed rush products in appearance, but a bit hard to the touch (but not very different from the above)

similar natural difficulties sometimes arise when weaving rushes ten in appearance, weft yarn on but similar non-woven fabrics in the Handle; unsatisfactory in terms of flexural rigidity

similar in appearance to natural rush products, but soft to the touch; unsatisfactory in terms of flexural strength

dto.

CO OO

Example 3

An acrylonitrile polymer composition was prepared by blending 60 parts of an acrylic polymer (molecular weight 58000) which consisted of 88% acrylonitrile and 12% methyl acrylate, 12 parts of a 3% aqueous Solution of sodium bicarbonate and 28 parts of acrylonitrile. The polymer mass was known in a usual manner Melt spinning apparatus at 137 ° C under autogenous pressure.

Thereafter, the melt was extruded into an atmosphere having pressure zone and the extrudate obtained was applied to 1.4 times in the longitudinal direction in a dry heat atmosphere at 120 ⁰ C stretched while achieving a synthetic rush-like molded body, which was the final product.

The synthetic molded article obtained in this way was in the shape of a rush plant. In the following table III the apparent cross section (S), the bulk density (Γι, the internal water absorption capacity and the stickiness behavior of the product according to the invention in comparison to the corresponding properties of the natural rush and a known polypropylene product on the market are listed.

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Table III

product according to the invention

Natural product

Polypropylene product

apparent bulk density water absorption feeling of cross section (g / cm ³ ) capacity (%) stickiness (cm ³ ) after

2 min 1 h

1.50x10

1.78x10 1.51x10

-2

-2

0.22

0.20 0.17

30.8 72.5

29.7 89.5 0.1 0.1

not determined

not determined

established

The results show that the synthetic according to the invention Product closely resembles the natural rush plant.

The obtained synthetic product was then placed in an ordinary tatami surface web loom and in a tatami surface web processed, which was light in weight and elastic like wall and floor coverings made of natural rush, and the gave a dry and refreshing feeling so that it never felt sticky, even in contact with sweaty Skin. The product obtained therefore has a very high commercial Value. An abrasion test and light stability test using a natural rush or synthetic resin according to the invention Molded Tatami product were carried out, showed that the latter is the former product with respect to the tested Properties was greatly superior.

Example 4

The continuous polymerization of acrylonitrile was carried out in a polymerization tank of 740 ml capacity, the was equipped with anchor-like impellers, a temperature

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temperature sensor and a pressure sensor, and also a jacket exhibited. The polymerization tank had a stainless steel feed pipe located at its bottom. The feed pipe was connected to several piston pumps. A needle valve was attached to the side wall of the tank and at the other end of the valve there was a nozzle with a very small opening of 1.3 mm in diameter. The flow range in the nozzle had a tap valve which was capable of enlarging or reducing the cross-section of the passage. Of the The jacket of the polymerization tank was fitted with a pipe that allowed steam or compressed air to flow through it. Of the The jacket was also equipped with sensor tubes to measure the temperature and pressure. those in the polymerization tank Melt equipped.

When the polymerization started, the needle valve was first completely closed and then the pumps were turned on to feed the following monomer mixture and an aqueous solution into the polymerization tank kept ^{at a temperature of 135 ° C.}

Monomer mixture: acrylonitrile / methyl acrylate / methyl methacrylate =

91 / 8.5 / 0.5 (feed flow rate 12.37 ml / min),

aqueous solution: containing 7% ammonium persulphate and 3.5%

Sodium bicarbonate (feed flow rate 2.23 ml / min).

As soon as the polymerization progressed and the polymerization tank with the polymer in the melted state was filled, the opening of the needle valve was adjusted so that the pressure in the tank was kept at 25 atmospheres. Then became by controlling the diameter of the faucet valve that was located between the needle valve and the outlet of the nozzle opening, the pressure of the flow area of the melt in the table

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IV varies in the manner indicated. In all cases the melt in the polymerisation tank was extruded through the die opening into a zone of atmospheric pressure while it was at its respective pressure. The extrudate obtained was then stretched to 1.3 times in length in a dry heat atmosphere at 120 ⁰ C to form the synthetic molding. The internal water absorption capacity and the bulk density of the synthetic moldings obtained in this way are also shown in Table IV below.

Table IV

Trial adjustment no. the pressure

1.5

Resin treatment

Bulk density Internal water absorption (g (cm ³ )) capacity

5
8th

8th
12th

12th
17th

not made

not made

performed

not made

not preconfigured

not made

aforementioned

not pre-genarenen

0.04

0.12
0.23

0.25
0.25

0.28
0.28

0.35

after
min

77.5

58.2
33.7

35.4
20.8

22.7
20.1

11.5

after 1 h

210.2

185.3 158.5

124.0 97.6

74.2 32.4

20.3

a trium bicarbonate was used in these experiments.

% aqueous solution of Na-

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Floor mats, which are made from the synthetic moldings according to the Trials Nos. 3 to 7 were very similar to those obtained from natural rush. The floor mats, which were produced from the synthetic moldings according to tests 1 and 2, were somewhat soft and unsatisfactory in terms of stiffness, and difficulties in weaving weft yarns also sometimes occurred on. In particular, the floor mat made from the synthetic molded body according to experiment no. 1 had a low abrasion resistance and was of no practical use. The floor mat made from the synthetic molding according to the experiment No. 8 had an improved hand and a considerably high water absorption capacity compared to known polypropylene products and therefore felt only slightly sticky, but it was made from natural rush Put something under the flooring.

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L e r s e i f e

Claims (13)

MÜIiJLBR-BOHE DEÜl'EL SCHÖN HEHT-ZI. June 8, 1973 DR.WOLFGANG MÜLLER-BORE (PATENT ADVOCATE FROM 1927 - 1973) DR. PAUL DEUFEL. DIPL.-CHEM. DR. ALFRED SCHÖN. DIPL.-CHEM. WERNER HERTEL. D1PL.-PHYS. J 1434 Japan Exlan Company Limited 25-1, Dojima Hamadori 1-chome, Kita-ku, Osaka, Japan Shaped body with a rush-like structure and process for its production Claims ii.) A rush-like shaped body, characterized in that it is composed of an acrylic polymer consisting of acrylonitrile alone or of acrylonitrile and at least one Ethylenically unsaturated compound is obtained and has a foamed structure. 2. Shaped body according to claim 1, characterized in that it has an average diameter of 0.5 to 5 mm having. 809883/0851 3. Shaped body according to claim 1, characterized in that that it has an average diameter of 0.8 to 4 mm. 4. Shaped body according to claim 1, characterized in that it has an average diameter of 1 to 2.5 mm. 5. Shaped body according to claim 1, characterized in that it has a bulk density of 0.05 to 0.8 g / cm ³ . 6. Shaped body according to claim 1, characterized in that it has a bulk density of 0.1 to O ₁ -5 g / cm ³ . 7. Shaped body according to claim 1, characterized in that it consists of an acrylic polymer that is more contains than 40 wt .-% acrylonitrile. 8. Shaped body according to claim 1, characterized in that it consists of an acrylic polymer that is more contains than 60 wt .-% acrylonitrile. 9. Shaped body according to claim 1, characterized in that it has an internal water absorption capacity of 5 to 200% 10. Shaped body according to claim 9, characterized in that that it has an internal water absorption capacity of 30 to 180%. 11. Shaped body according to claim 9, characterized in that it has an internal water absorption capacity of 10 to 60% when immersed in for two minutes 809883/0851 Has water. 12. Shaped body according to claim 9, characterized in that that it has an internal water absorption capacity of 20 to 50% when immersed in for two minutes Has water. 13. A method for producing a rush-like shaped body according to claim 1, characterized in that an acrylic polymer composed of acrylonitrile alone or acrylonitrile and at least one ethylenically unsaturated compound is dry-spun, wet-spun,
semi-melt-spun or melt-spun and into the polymer solution or during the spinning process
Polymer melt a) introduces a heat blowing agent, b) introduces a volatile liquid, or c) blowing in air, carbon dioxide or nitrogen gas, or a polymer solution or polymer melt prepared at high temperature and high pressure in a zone of lower pressure is extruded. 809883/0851