DE102016015832A1 - Pin with integral injection-molded layer sleeve - Google Patents

Abstract

A pen for applying a color and / or cosmetic substance, comprising a refill of the substance to be applied and a refill molding, integrally injection molded sleeve of a thermoplastic material consisting of a mixture of a first and a second plastic, wherein the sleeve, respectively Seen in the radial direction, having an outer enrichment zone with a higher concentration of the first plastic than in the central region and that the sleeve, viewed in the radial direction, has an inner enrichment zone with a higher concentration of the first plastic, as in the central region.

Description

PEN WITH ONE PIECE OF SPLASHED COAT

The invention relates according to the preamble of the respective main claim a sharpenable pencil, in particular a cosmetic pencil, and a method for its production.

STATE OF THE ART

Cosmetic pencils are widespread, in which the mine is picked up by a wooden pin sleeve. The wooden pen sleeves can be easily sharpened with the help of a sharpener and a sharpener that works on the principle of a pencil sharpener.

The production of wooden pen cases is quite expensive from the start. For this, wooden boards must be shaped, glued and then separated by milling.

Where such pens need not be made as pencils or crayons, but as cosmetic pencils, there are other specific problems.

Cosmetic pencils usually require a higher quality wood than crayons. This is because, as a rule, cosmetic pencils should have a more uniform lace pattern. In addition, cosmetic pencils require a more or less complex surface finish. The individual pins are usually simply or repeatedly painted or coated. Because especially in comparison to a single crayon high-priced cosmetic pencils should give the buyers optically and haptically a special high quality.

A typical, with respect to the mine mass as such uncritical method for producing such pins is to extrude a suitable lead mass and glued into grooved boards or insert in plastic sleeves. This process corresponds to the process which has proven itself for the production of colored pencils. A disadvantage of these extrusion processes is that, as a rule, only mining masses can be used which lead to relatively hard mines. Because the mines must remain manageable during further processing - too soft mines threaten to deform when they are inserted in the subsequently zusammenzuleimenden boards. However, hard mines are often undesirable, especially in the case of cosmetic pencils, since they exhibit a so-called harder application in that a satisfactory amount of cosmetic can be removed from them only under relatively high pressure.

Because of this, in the field of cosmetic pencil production, a different method of manufacturing the mine is often used. In this procedure, the cosmetic mass is poured hot into prefabricated stem sleeves with a concentric hole where the lead mass cools. Here, however, there is the problem that cosmetic compositions may have a relatively high proportion (in the hot state) of volatile constituents. These volatiles tend, at least over time, to diffuse or migrate in the cooled state as well.

For cosmetic pencils with such soft mines therefore also requires the inner surface of the wooden pin sleeve, which receives the mine, a separate pretreatment - if any wooden sleeve is to be used. Special measures are required because it must be prevented that volatile constituents of the mine diffuse into the wood or migrate even in the wood, thereby depriving the mine and possibly affect the painting on the outside surface. Incidentally, this problem can also arise in plastics, especially in foamed plastics. In plastics too, volatile constituents can diffuse in and, if they have penetrated the plastic intensely enough after some time, may possibly impair the outer surface.

To remedy this problem, proposes the German patent application DE 2 834 479 to build a cosmetic pencil with a grease mine, which is provided with a metallic sheath before it is inserted into the sleeve. A metallic sheath is a good barrier, but produces unnecessary effort. In addition, it is also a hindrance when tipping the pen. Although the metallic sheath can be very thin and quasi formed by a film. However, the long, narrow strips of foil cut off with the sharpener tend to become entangled, because unlike the cut wood shavings, there is no chip breakage here.

The same problem is addressed by the German patent application DE 31 37 4 86 A1 , Here it is proposed to introduce the lead into a tube made of a sprayable plastic material, wherein the tube is coated on the outside with a solvent-impermeable layer, such as in the form of a plastic film made of polyester. Such a construction is not only expensive, but also can not meet the high optical and haptic requirements that are placed on a cosmetic pencil. In addition, when applied as a shrink tube, the film may wrinkle or generally form undesirable overlaps. Incidentally, the installation of a plastic film Also problematic because the plastic film is cut at the point of sharpening and not always cut clean, so that the pointed end risked to look immediately unsightly. In addition, the problem already mentioned above for the metal foil of missing chip breakage arises. These problems are known to those skilled in the art, even if nothing is said about Anspitzbarkeit in said patent application.

Also the European patent EP 0 613 634 B1 is dedicated to this problem. Here it is proposed to form a combined pin sleeve, which consists of a thin-walled plastic tube, which is inserted into the receiving opening of the actual pin sleeve. After assembly of these two parts then the mine is poured. Obviously, the inserted, thin-walled plastic tube has the task to seal the mine and to remain dimensionally stable beyond the casting temperature of the mine. Due to its thinness it does not stand in the way of sharpening, even if comparatively hard plastic is used. In contrast, a good pinable plastic can be used for the actual pin sleeve, which must take no account of the diffusion behavior of the mine components.

In general, there is a multiple conflict of objectives in the production of one-piece plastic tube sleeves.

On the one hand, it is necessary to use a plastic that is soft enough to allow sharpening with the help of a sharpener that operates on the principle of the manual pencil sharpener. Then the plastic must be dimensionally stable beyond the casting temperature of the mine at the same time. Finally, the plastic must form a surface as attractive as possible in order to provide the desired optical, haptic and high-quality appearance with the least possible reworking.

In order to find a useful compromise in this respect, often come from home relatively hard plastics for the production of the pin sleeve used. These show the necessary consistency. The Anspitzbarkeit is here usually ensured by the fact that the plastics are foamed. However, foamed plastics can not be processed by means of injection molding, but make it necessary to produce the pin barrel by extrusion. By foaming and extruding but suffers the surface quality, so that such pen cases are not readily available without aftertreatment.

An example of this is the U.S. Patent 5,360,281 , claimed the protection for pen sleeves made of foamed plastic. Although this patent also addresses the idea to produce pen sleeves by injection molding, but the idea has not been included in the claims - obviously, because the proposed plastics are not foamed show too poor Anspitzbarkeit.

• ➢ mindestens einem Styrol-Butadien-Copolymer,
• ➢ sowie mindestens einem Styrol-Butadien-Styrol-Blockcopolymer,
• ➢ und mindestens einem weiteren Kunststoff aus der Gruppe der Styrolpolymere, Styrol-Acrylnitril-Polymere, der Acylnitril-Butadien-Styrol-Polymere, der Acryl-Styrol-Methylmetacrylate oder einer Kombination der genannten Kunststoffe,
• ➢ sowie mindestens einem Hilfsstoff besteht.

Finally, that is still US Patent Application 2013/0121747 A1 to name, which has set itself the goal to provide pens with a chemically and mechanically particularly secure pin sleeve. This is to be achieved by choosing a plastic compound that will not release VOCs during manufacture and use and will break without splintering so that the corresponding pins are also suitable for small children. In addition, the pins should also be easy to sharpen. To solve this problem, the said US patent proposes that for the production of the pen sleeves a plastic mixture is used, consisting of

• ➢ at least one styrene-butadiene copolymer,
• ➢ and at least one styrene-butadiene-styrene block copolymer,
• ➢ and at least one further plastic from the group of styrene polymers, styrene-acrylonitrile polymers, acylnitrile-butadiene-styrene polymers, acrylic-styrene-methylmetacrylates or a combination of said plastics,
• ➢ and at least one excipient.

With the above-mentioned problems in the production of cosmetic pencils, this patent application is not concerned. In particular, the application is concerned neither with the problems encountered in mine-casting nor with the problem of how to achieve a high-quality exterior surface. Even for the recognized problem of migrating mine constituents, this US patent does not provide a satisfactory solution. The US patent proposes to counteract the drying out of mines by adding wax to the plastic mixture from which the sleeve is made. However, this solution is inadequate, especially in the cosmetics sector, since it can not be guaranteed that the technical waxes added to the plastic do not in turn migrate into the mine, which is undesirable because the mine is intended to deliver only cosmetically acceptable and harmless substances in a defined amount.

THE PROBLEM OF THE INVENTION

In contrast, in a first step, it is an object of the invention to provide a pen for application specify a color and / or cosmetic substance, which has a one-piece, made entirely of plastic sleeve, which can preferably be sharpened by means of a pencil sharpener by hand and has a preferably shiny, high-quality outer surface, which requires no reworking after injection molding, with the exception the attachment of a possible label or other, mostly local decorations.

THE INVENTION SOLUTION

The pen according to the invention has a refill of the substance to be applied, with or without volatiles, and a refill, integrally and uniquely injection molded sleeve of a thermoplastic material consisting of a mixture of a first and a second plastic, each of which, in Pure form, has different properties. "Single-material" injection-molded means in the sense of the invention that only a single material (even if it is a mixture in itself) has been injected into the mold cavity, usually in a single shot, exceptionally in several successive shots. This is in contrast to the "overmolding", in which only a first material is injected into the mold cavity and then - from a different stock of material - a second material, the other property is sprayed.

The pin according to the invention is characterized in that the first and the second plastic are selected such that they partially separate by the injection molding and thereby form a sleeve which behaves after cutting the outer peripheral surface such that a chip from the outer peripheral surface protrudes and then with bare hands by pulling on the chip a skin can be removed from the surface of the sleeve.

As a preferred development, but also independently thereof, in isolation, protection is claimed for a pin according to the invention, which is characterized in that the first and the second plastic are selected so that they partially separate by injection molding and thereby form a sleeve which, viewed in the radial direction, has a higher concentration of the first plastic in the region of its surface of the outer periphery (outer enrichment zone) than in the middle (central depletion zone).

At the same time, the first and the second plastic may optionally be chosen such that the sleeve also has a higher concentration of the first plastic in the region of the surface of the inner periphery (inner enrichment zone).

The pencil according to the invention is further characterized in that it can be sharpened by means of a sharpener working on the principle of a pencil sharpener, d. H. by turning the pen by hand.

• ➢ Es lässt sich dreimal unmittelbar hintereinander mit dem Hand-Spitzer an dem Ende des Stiftes, dessen durchgängiger Kegel dem Winkel entspricht, in dem die Spitzerklinge angeordnet ist, ein über mindestens fünf, besser mindestens acht volle Stiftumdrehungen durchgehender Span abnehmen. D. h. der Span bildet eine durchgängige Locke, vorzugsweise mit über die ganze Länge hinweg konstant bleibender Dicke (+/-10% schwankend) und idealerweise ohne, dass im Mittel ein Dickenanstieg von mehr als 15% besser nur 10% zum Ende des Spans hin zu beobachten ist.
• ➢ Die im Regelfall kegelige Schnittfäche, die ein solcher Spitzer hinterlässt, ist dabei vorzugsweise gleichmäßig glatt. Sie weist (abgesehen von der örtliche Absetzkante, welche die von der Spitzerklinge bei Abbruch des Anspritzvorgangs erreichte Position markieren kann) vorzugsweise gar keine lokalen Ausbrüche, Absplitterungen oder Stufen z. B. in Gestalt von Rattermarken auf oder zeigt jedenfalls keine lokalen Ausbrüche, Absplitterungen oder Stufen mit einer Tiefe von mehr als 0,3 mm.

In order to determine whether a pencil can be sharpened according to the invention, there are various alternative criteria that are cumulatively fulfilled in the ideal case:

• ➢ It can be three times immediately in succession with the hand-sharpener at the end of the pin, whose continuous cone corresponds to the angle in which the sharpener blade is arranged to remove at least five, more preferably at least eight full pen rotations continuous chip. Ie. the chip forms a continuous curl, preferably with a thickness that remains constant over the entire length (+/- 10% fluctuating) and, ideally, without an average increase in thickness of more than 15%, better only 10% towards the end of the chip is.
• ➢ The usually tapered cutting surface left by such a sharpener is preferably uniformly smooth. It has (apart from the local Absetzkante, which can mark the position reached by the sharpener blade when aborting the Anspritzvorgangs) preferably no local outbreaks, chips or steps z. B. in the form of chatter marks or shows any case no local outbreaks, chipping or steps with a depth of more than 0.3 mm.

It is usually the second plastic, which is chosen so that it is ensured that the sleeve can be sharpened by means of a sharpener in the manner of a pencil sharpener. The measure for this is a comparison with a pin having an identically sized sleeve which is made entirely of the first plastic and can not be sharpened in the manner described.

So you get in a train, so to speak, a multi-layered sleeve, as you can produce so far only with a much more expensive overmolding process, in which only one sleeve part of the first material is injected and then, after pulling movable slide, the second sleeve part is sprayed from the second material.

The pen according to the invention is characterized in that the properties inherent in the first plastic in its purest form are strikingly pronounced on the surface of the outer circumference and the inner circumference by its enrichment with the help of injection molding, even if even directly on the respective surface certain proportion of the second plastic is encountered. In this way, the first plastic causes a layer with a high surface quality to be formed on the surface of the outer circumference of the pin sleeve, in one and the same original molding process. The surface can be absolutely flat and mirror-smooth with the right choice of the first plastic - seen with the naked eye. In addition, a layer with a blocking function is formed on the surface of the inner circumference of the pin sleeve. This lock function will be explained later. It has a positive impact on mine casting and / or mine shelf life.

According to the invention, a division of responsibilities is provided here. The first plastic is chosen so that an excellent surface quality can be achieved. If the first and second plastic materials are properly matched so that the necessary mix is achieved, then a surface can be achieved in this way, which shows specular gloss, comparable to the gloss of a piano lacquer.

When choosing the first plastic, no consideration has to be given to the need for sharpening. Because the outer enrichment zone, in which the first plastic on the outside preferably to more than 80 wt .-%, better to more than 90 wt .-% enriched, can be kept thin in the radial direction - possibly significantly thinner than the overmolding.

The same is usually true for the inner enrichment zone, in which the first plastic on the inside enriches at least to ≥70% by weight.

Ideally, the extension R _AA or R _{IA of} the outer and / or the inner enrichment zone is 0.075 to 0.5 mm, more preferably only up to 0.35 mm, measured from the surface of the outer or inner circumference in the radial direction inwards. Thus, the first plastic does not hinder the Anspitzbarkeit, even if it tends tend to be badly machined.

It has proved to be advantageous for the realization of the respective function when the inner enrichment zone has a slightly smaller radial extent R _IA than the outer enrichment zone, the radial extent of which is R _AA . Preferably, therefore, R _AA > R _IA, and ideally even R _AA > R _IA * 12/10.

With correspondingly intensive cooling of the injection mold, where it forms the outer enrichment zone, it is possible to achieve that the free surface of the outer enrichment zone is at least 95% by weight, in some cases even 97% by weight or more, of the first plastic ( and any pigments incorporated therein).

Within the entire outer enrichment zone, the proportion of the first plastic is ≥ 80% by weight, much better 90% by weight.

With correspondingly intensive cooling of the injection mold, where it images the inner enrichment zone, it is possible to achieve that the proportion of the first plastic within the entire inner enrichment zone is at least 67% by weight. better at ≥ 70 wt .-% is.

Corresponding to this goes i. d. R. associated with a central depletion zone. Within this central depletion zone, which is in the middle of the sleeve, the local weight percent of the first plastic is less than the weight percent of the first plastic in the injection molding mix provided by the injection. In any case, the term center of the sleeve designates a range of +/- 0.75 mm or at least +/- 0.5 mm around the range of the radius, which is the mean value of the radius at the surface of the outer circumference and the radius at the surface calculated on the inner circumference, wherein in non-round contours of the average radius is applied.

Depending on the proportion of the first plastic to the injected into the mold cavity plastic mass, the proportion of the first plastic within the entire central depletion zone is preferably at least ≤ 60 wt .-% better ≤ 55 wt .-%.

On the other hand, for the second plastic, a plastic can be selected which, where it forms a significant part in the formation of the plastic structure, reduces the strength of the first plastic, even if the first plastic optionally has the higher proportion by weight of the total mixture. In the choice of the second plastic, no consideration must be given to the surface quality and / or its blocking capability with respect to mine components, since the second plastic is not involved in shaping the surfaces.

The manufacture of the sleeve of the pen by injection molding gives the pen in the present case a certain physical condition. Because only the injection molding leads in the present case to the fact that the first plastic accumulates on the surface of the outer periphery and thereby forms the possibly piano lacquer-like surface - although the first and the second plastic have been uniformly mixed before injection into the injection mold.

Although the reasons why such a segregation occurs are not fully understood. Nevertheless, it can be seen that the Impact of the mixture of the first and the second plastic, which is injected into the mold, on the well-cooled surface of the mold cavity initially leads to a rugged cooling. This cooling causes a segregation, because one plastic solidifies faster than the other plastic.

In this way, the well-cooled surface of the mold cavity is covered with a layer which consists entirely or predominantly of the first plastic. The resulting layer is usually very firm or stronger than the underlying core, since the proportion of the second plastic in it can develop no formative interference.

Since the said layer is an insulation due to its poor thermal conductivity, a further abrupt cooling is prevented. As a result, the segregation below the said layer decreases, usually rapidly. In the middle, therefore, the mixture of the first and the second plastic as such also remains in the course of solidification, even if, as a rule, there is a change in the percentages by weight. Since the second plastic disturbs the microstructure, the solidified layer in this area is less strong than the said layer which has formed on the cooled surface of the mold cavity.

The term sharpener or pencil sharpener here refers to the classic pencil sharpener, as it is used for pencils, crayons and cosmetic pencils. Such a pencil sharpener has a body made of metal, wood or plastic, which has a tapered receptacle for the tip of the pin to be pointed and at least one blade, which decreases by appropriate turning of the pin by hand, a chip from the tip.

As used herein, the term thermoplastic material refers to a material that can be heated to a viscous state in which it can be injection molded. The term covers classic thermoplastics and TPEs.

The first and the second plastic are chemically different, so usually belong to different classes of materials or types of plastic.

The above definition of the various terminology also applies to what has been said below, unless clearly different from the context.

PREFERRED TRAINING OF THE INVENTION

The concentration of the first plastic preferably decreases continuously from the outer enrichment zone and from the inner enrichment zone toward the center.

This distinguishes the pen according to the invention or its multi-layered sleeve from known sleeves, which only receive their two-layered or multilayered structure in that a continuous additional plastic layer, a continuous film, a continuous lacquer layer ("piano lacquer") or the like has been applied.

Of course, in the end, the sleeves according to the invention, in particular for partial additional decoration, can also be provided with further plastic or lacquer layers and foils, e.g. for the purpose of labeling.

Preferably, the sleeve is formed over its entire cross section away from both the first and the second plastic, but the two plastics are found in locally different weight fractions, usually such that the weight fractions continuously along the cross section (seen in the radial direction) change , The term "entire cross-section" in some cases does not include the boundary layer in the range up to 0.2 mm below the surface of the outer circumference. The same may apply to the surface layer in the range up to 0.2 mm below the surface of the inner circumference.

Ideally, the sleeve has a separate layer only near the surface, for. In the form of the peelable skin as explained below, and does not have a slate-like structure throughout the cross-section. Because this would undesirably increase the tendency that the chip peeled off when sharpening involuntarily crumbles into very fine crumbs and thus causes contamination, even at the cosmetics mine.

The barrier layer can be a mechanical barrier layer which is very smooth and thereby prevents air pockets from being formed during casting of the mine - as is often observed when refills are poured into wooden sheaths whose inner surface is relatively rough.

The barrier layer may instead or at the same time be a chemical barrier layer, which is clearly preferred. Such a barrier is characterized by limiting migration of mine components. Depending on the choice of the first plastic in particular the migration of isoparaffins and silicones is limited and / or the migration of water and polar volatile substances, such as. B. alcohols. It does that if it lowers the migration at least to the extent that no noticeable impairment (hardening / dehydration) of the mine is recorded, even after a Storage of 12 months at a constant temperature of 23 ° C not. Of a barrier layer in the strict sense, one speaks in any case when the first plastic (in pure form) to isoparaffins and silicones and / or to water and polar volatiles such. As alcohols, a smaller diffusion coefficient, as the second plastic in pure form.

It has proven to be particularly advantageous to use as the first plastic a weakly polar plastic having an electronegativity difference ΔEN in the range between 0.3 and 0.5, but which has a monomeric component or a block which has weak interactions with another, highly polar plastic, so that an immediate spontaneous segregation is prevented. The electronegativity difference .DELTA.EN is understood here and below to mean the maximum electronegativity difference between adjacent atoms in the polymer structure.

It is particularly advantageous to use a plastic from the class of styrene-acrylonitrile or acrylonitrile-styrene copolymers (abbreviation: SAN, nomenclature here and everywhere according to DIN EN IDSO 18064), preferably in pure form. SAN is weakly polar, but it can also interact with other highly polar plastics through its acrylonitrile content.

A preferred composition consists of 65 wt .-% to 80 wt .-% of styrene and 20 wt .-% to 35 wt .-% of acrylonitrile, as well as each different molar masses. A particularly favorable composition consists of 70% by weight of styrene and 30% by weight of acrylonitrile fractions (each with +/- 1.5% by weight of tolerance). Ideally, the styrene-acrylonitrile marketed under the trademark "LURAN 378P ™" by BASF SE, Ludwigshafen, Germany, is used.

The styrene-acrylonitriles, and in particular LURAN 378P ™, are distinguished in their (not at all or not materially) mixed with other plastics by their chemical resistance, in particular amines, which are often used as neutralizing agents in cosmetic compositions. The styrene-acrylonitriles and in particular LURAN 378P ™ are further distinguished by their heat resistance. These properties are used here in connection with the segregation according to the invention in the course of injection molding in order to give the surface on the inner circumference of the sleeve their superior properties.

At the same time, the styrene-acrylonitriles and in particular LURAN 378P ™ are characterized by their excellent appearance on the surface, which is used here in conjunction with the segregation according to the invention in the course of injection molding to the surface on the outer circumference of the sleeve, the necessary surface quality to rent.

The styrene-acrylonitriles, and in particular LURAN 378P ™, are known to have inherently high strength, especially high scratch resistance, and are brittle. Therefore, sleeves made of pure styrene-acrylonitriles can not easily be sharpened by a pencil sharpener with normal force.

The second plastic is selected according to the invention so that it weakens the strength of the first plastic where the sleeve does not need to be embossed by the special properties of the first plastic.

In general, it can be said that the second plastic should preferably be a plastic that physically crosslinks in the course of injection molding via segregation phenomena from the SAN and in itself by microphase separation to form partially crystalline regions.

Preferably, the second plastic is a polar plastic having an electronegativity difference ΔEN in the range> 0.5 and 1.7.

It has proved to be particularly advantageous to use a plastic from the class of polar thermoplastic elastomers (short name TPE-ET) as the second plastic, preferably in pure form.

In particular, such TPE-ET are used, which use a polyether group as a soft segment. The use of the subclass belonging to this class of polar thermoplastic polyester elastomers or polar thermoplastic copolyesters (short name TPC-ET) has proven particularly favorable. Typically, this plastic consists of a block copolymer with alternating hard and soft sections, the chemical interactions are essentially ester- and / or ether-based dipolar interactions. Ideally, the polar thermoplastic copolyester produced under the trademark "Arnitel EM400 ™" by DSM Engineering Plastics BV, Urmonderbaan 22, 6167 RD Geleen, The Netherlands is used.

The amazing thing is that the mixture of the first and second plastics just described, where they are not largely segregated (in the sense that the SAN concentration does not fall below 90 wt .-%), has a lower strength than would be expected per the individual components. Due to this, a good Anspitzbarkeit sets. Here, the only conditional resistance of the second plastic to the volatile constituents of soft mining masses plays no role, since the first plastic on the surface, which comes directly into contact with the lead mass, forms a barrier layer, as described. In addition, the fact that a reflective surface can not be achieved with a TPE or TPC-ET also plays no role.

Alternatively, a plastic from the class of acrylonitrile-ethylene-propylene-styrenes (AES) can be used as the first plastic. Ideally, the acrylonitrile-ethylene-propylene-styrene marketed by ROMIRA Gesellschaft für Vertrieb & Verarbeitung of Chemieprodukte mbH, Pinneberg, Germany under the brand name "ROTEC A702 ™" is used.

In principle, a system is conceivable in which the first plastic contains from 20% by weight to 80% by weight, the second plastic from 80% by weight to 20% by weight, and the filler metal Auxiliaries have a weight fraction of 0 wt .-% to 30 wt .-%, more preferably only up to 15 wt .-% possess. Impurities of all kinds are not desirable and are preferably avoided above the per mille range, in particular above 15% by weight. If this is not successful in individual cases, impurities up to 5 wt .-% better up to 2.5 wt .-% can be tolerated.

An adjustment of the system, in which the first plastic has a weight fraction of at least 45% by weight, better at least 55% by weight, has proven to be particularly favorable for the realization of the effect according to the invention. In most cases, the recommended upper limit for the first plastic will then be 75% by weight, better still 65% by weight. Fillers or auxiliaries with a weight fraction of up to 15 wt .-%, better only up to 5 wt .-%, may be added.

Surprisingly, it has been found that the addition of other plastics to the two-system (SAN or AES and ausTPE-ET or TPC-ET) can affect its simplistic adjustability. Therefore, the first and the second plastic form at least the majority of the plastics used for the sleeve. This means that the sleeve according to the invention consists of the first and the second plastic in that they form the majority of the plastic mass or provide in some cases at least 90 wt .-% of the plastic material used. The best case is that the first and the second plastic and the pigments and auxiliaries added thereto, or only the two plastics, together with the pigments added to them, form all the plastics material used for the sleeve, apart from impurities.

Otherwise, as stated, fillers that affect the plastic matrix but are not involved in its construction and adjuvants, such as pigments, may be added. Gas or foaming agents in amounts that affect the injection molding are to be avoided, preferably completely avoided.

The auxiliaries also include those plastic components which are poured into the matrix from the first and the second plastic only in the manner of auxiliaries and which are not melted in the course of injection molding, for example a crosslinked elastomer added as a filler in ground form thermoset. Preferably, however, such fillers, which themselves consist of plastic, are avoided, since they can increase the viscosity and can hinder the separation.

Preferably, the first plastic is selected so that the sleeve on the outer peripheral surface has an arithmetic average gloss level GU of more than 30 GU, better more than 40 GU. The measurement is carried out according to ISO 2813 over a distance of 10 mm with 10 evenly spaced measuring points in the direction along the longitudinal axis L at a measuring angle of 60 °.

Further effects, advantages and design options of the invention can be found in the embodiments described below.

list of figures

• The 1 shows the sleeve of a pin according to the invention in the central longitudinal section.
• The 2 shows the entire pen according to the invention in the central longitudinal section.
• The 3 FIG. 12 is a fragmentary enlargement showing part of the fracture surface of a sleeve torn apart along its longitudinal axis. FIG.
• The 4 shows a section perpendicular to the central longitudinal axis through the sleeve of a pin according to the invention.
• The 5a shows the skin removal test at a glance, at the beginning, after cutting.
• The 5b shows the skin removal test in the course of further progress in detail.
• The 6 shows the respective RAMAN spectrum for SAN and TPC-ET.
• The 7 shows the RAMAN spectra for SAN and TPC-ET for the pure substances and at 2 different measuring points 100 and 200 at the cut surface of the sleeve.
• A 8th is not scheduled.
• The 9 Figure 4 shows the RAMAN intensity of the spectra taken for samples containing 0% by weight of SAN, 30% by weight of SAN, 50% by weight of SAN, 70% by weight of SAN and 100% by weight of SAN and contained the complementary portion of TPE-ET.
• The 10 illustrates in which steps the cut surface of the sleeve, which was manufactured according to the first embodiment, was measured with the RAMAN spectra copy.
• The 11 shows how the concentration of SAN and TPC-ET changes in the radial direction across the cross-section of the sleeve.

EMBODIMENTS

First embodiment

For the first embodiment, 60 wt .-% SAN (LURAN 378P ™) and 40 wt .-% TPC-ET (Arnitel EM400 ™) with the addition of 3% pigments (preferably black pigments of the marketable type Carbon Black CI 77266, which at different Companies are brought to the injection-moldable, viscous state to a temperature of preferably 250 ° C +/- 10 ° C., while evenly mixed.Other fillers or auxiliaries are not added.This can be an extruder from Leistritz, 90459 Nuremberg / Germany, serve.

The actual injection molding process can be carried out on an injection molding machine of the E-motion 940 / 160T type from Engel, 90451 Nuremberg / Germany. The prepared mass is injected at an injection pressure of about 1400 bar in the mold cavity of the injection mold. The injection mold is cooled by a liquid medium, which flows through the injection mold - sealed against the mold cavity. In particular, the core pin of the injection mold, which images the cavity provided for later receiving the lead in the sleeve, is itself cooled directly by the liquid medium. This means that the core pin itself is traversed by the cooling medium.

It is then removed from the mold, preferably by pulling the core pin together with the sleeve out of the mold cavity and then pushing the sleeve off the core pin.

The sleeve thus produced 2 especially preferably looks like that 1 illustrated, with the structural details of the sleeve 2 will be discussed later.

The sleeve thus produced shows a very scratch-resistant outer peripheral surface with piano lacquer-like gloss. It is very resistant to migration of mine components and well decoratable.

To get a cross-section, which is visually accessible to an examination, became the sleeve 2 according to 1 clamped in a tensile machine and by correspondingly large tensile forces in the direction of its longitudinal axis L torn apart in half. A cut-out enlargement of the resulting fractured surface of the cross-section, which was obtained through a microscope-assisted initial optical inspection 3 show the 3 ,

Already based on the 3 It can be seen that it is at and just below the surface of the inner circumference 5 and the outer circumference 4 came to the formation of a different layer. This finding was verified by measurements using Raman spectroscopy, as explained in more detail below. This results in what is based on the 4 is shown.

As you can see, the one outer enrichment zone 6 and an interior enrichment zone 7 determine. The expression of the outer enrichment zone 6 and the interior enrichment zone 7 can be influenced by the temperature of the surface inside the mold cavity. The colder the corresponding surface of the mold cavity at the beginning of the injection, the more pronounced the segregation. This also applies to the inner enrichment zone 7 , As already mentioned above, the temperature of the core pin imaging the inner enrichment zone can be controlled by flowing the coolant through the core pin more or less intensively.

In the present case, no proportion of the second plastic can be detected on the free surface of the outer enrichment zone with the RAMAN spectroscopy within the scope of the measurement accuracy. This is not only desired in the context of this embodiment, but generally preferred. Because such a design is favorable for achieving the desired here, like a piano finish surface, shiny surface. In the radially inward direction below the free surface, the proportion of the first plastic begins to decrease. However, up to a depth of about 0.2 mm, a proportion of the first plastic of more than 90% by weight is present.

It is interesting that at least in the area of the outer enrichment zone there appears to be a defined boundary layer, from which the strength of the plastic forming the wall of the sleeve decreases significantly. When cutting a sleeve produced in accordance with this first exemplary embodiment, obliquely with a blade, so that an obliquely projecting chip is produced, like that 5 Illustrated, then, by pulling on the chip, it is possible to peel a skin off the surface of the sleeve with bare hands, regardless of the depth of the incision. The skin is relatively firm and tears in most cases only after 4 cm Abzugslänge and more.

In general, with effect beyond this embodiment, it can be said that such skin peel tests have shown that a particularly good Anspitzbarkeit is always given when such skins can be deducted with a thickness of 0.08 mm to 0.25 mm.

As far as can be explained so far, it seems that the sharpener blade is then not dependent on having to cut completely the relatively firm skin, but it seems to come to a mixture of cut and tear, which has a facilitating effect.

Second embodiment

To prepare the second embodiment, 60% by weight AES (ROTEC A702 ™) and 40% by weight TPC-ET (Arnitel EM400 ™) are added to a temperature of preferably 250 with the addition of 3% pigments (preferably black pigments of the abovementioned type) ° C +/- 10 ° C brought into the injection-moldable, viscous state while evenly mixed. Other fillers or auxiliaries are not added.

The processing of this mass takes place, as described above for the first embodiment, using the machines described therein, also by way of injection molding.

The sleeve thus produced 2 especially preferably looks like that 1 illustrated.

The sleeve thus produced shows a very scratch-resistant outer peripheral surface with semi-gloss. It is resistant to the migration of mine components and is easy to decorate.

The investigations with the aid of RAMAN spectroscopy, as explained in more detail below, show that also during the injection molding of this plastic mixture sets a clearly recognizable outer enrichment zone and an equally clearly recognizable inner enrichment zone whose extent depending on the intensity of the cooling of the injection mold within the areas described above.

Comparative example

For the comparative example, 60% by weight of SAN (LURAN 378P ™) and 40% by weight of a regular non-polar SBS block copolymer (ALLRUNA W55 ™) are added with the addition of 3% of pigments (preferably black pigments of the above-mentioned type) a temperature of preferably 250 ° C +/- 10 ° C brought into the injection-moldable, viscous state while evenly mixed. Other fillers or auxiliaries are not added. ALLRUNA W55 ™ is a trademark of ALLOD Werkstoff GmbH & Co. KG, 91593 Burgbernheim, Germany

The processing of this mass takes place, as described above for the first embodiment, using the machines described therein, also by way of injection molding.

The sleeve thus produced 2 especially preferably looks like that 1 illustrated.

The sleeve thus produced shows a matte outer surface and neither a significant outer enrichment zone nor an inner enrichment zone. Instead, the materials remain substantially homogeneously mixed until solidification. Also, the skin peel test can not be performed because the sleeve evidently has a homogeneous strength.

RAMAN spectroscopy for concentration determination

For the determination of the concentrations found especially in the outer and inner enrichment zone according to the invention, RAMAN spectroscopy is the means of choice.

For performing a Raman spectroscopy, the fracture surface described above proved to be poorly suited. Instead, the investigations were carried out on a cross-section, which was created by the fact that the sleeve was initially cut transversely to its longitudinal axis or sawed through and then the cross section thus obtained was sanded.

To clarify the local proportions of SAN and TPC-ET, the RAMAN spectra were measured across the cross-section of the sleeve produced in accordance with the first embodiment. The measurement was carried out using a RAMAN spectrometer from the Almega series from Thermo Fisher Scientific, 168 Third Avenue, Waltham, MA USA 02451.

To calibrate the device and to be able to assign the individual parts of the respective spectrum, the raw materials were first measured. This means that 100% by weight of SAN and 100% by weight of TPC-ET were produced. As long as a measuring point lies completely on the respective plate and the thickness of the plate 2 Exceeds 10 mm, the dimensions of the specimens play no role. Both plates were individually measured individually.

The spectra thus obtained were in the diagram according to 6 entered. The dotted line shows the spectrum recorded for SAN, the solid solid line shows the spectrum recorded for TPE-ET.

For the SAN determination, the area of the peak was used, which reaches its maximum at 3050 cm ^-1 , the area of the peak characteristic of the SAN, the maximum at 2250 cm -1, could also be used, it provides comparable Values and therefore need not be considered separately in the following, but may go unnoticed.

Then in succession the in 4 Marked points 100 and 200 measured. The two recorded spectra were superimposed, just as the 7 shows. One can already see that in the points 100 and 200 different concentrations of SAN and TPC-ET are encountered.

Then, in addition to the above-mentioned samples with 0 wt .-% and 100 wt .-% SAN systematically different mixtures of SAN and TPC-ET were prepared and processed by suitable temperature control surface layer to the said plates, namely mixtures containing 30 wt. %., 50% by weight. Contained 70% by weight of SAN and the complementary portion of TPC-ET. The RAMAN intensity of the spectra recorded for each representative of this series of samples has been entered in the diagram containing the 9 shows. At the 9 it can be seen that each mixing ratio is assigned a characteristic RAMAN intensity, and that there is a linear relationship between the percentage by weight of the SAN, or of the TPC-ET, and the respective intensity of RAMAN to be measured for this purpose.

Then - as already described - the ground cross section of the sleeve produced in accordance with the first embodiment 2 Measure step by step, just like that 10 illustrated. It was coming from the outside in the radial direction progressing point at / next point measured to the middle of the sleeve cross section and coming from the inside coming in the radial direction progressing point by point to the middle of the sleeve cross section.

These measurements give the diagram that the 10 shows. The plastic mass used for injection molding had a mixing ratio of 2/3 SAN to 1/3 TPC-ET. On this basis, taking into account the scattering of the measurement results, it can be seen that a partial separation has occurred during the injection molding process in the injection molding tool.

The concentration of SAN on the surface of the outer peripheral surface of the sleeve is about 100 wt .-%.

On the surface of the inner circumferential surface, the concentration of SAN is only about 70 wt .-%.

The structural design of the pin according to the invention

The pen according to the invention 1 is designed like the one 2 . 3 and 4 demonstrate. He usually has an outer diameter of about 6 to 16 mm.

In his center he has a recording for the mine 8th , which advantageously forms a positive rotation. Their cross-section may be circular, but is preferably designed to be oval, or polygonal, or 8-square, for a better grip between the mine 8th and the sleeve 2 to ensure. The distance between two opposite flat sides of the octagon is preferably between 3 and 5 mm. The wall thickness of the sleeve 2 is preferably in the range of 1.5 to 3 mm. The length of the pen 1 ie its extension in the direction of its longitudinal axis L , is usually greater than 85 mm, usually greater than 100 mm up to 180 mm.

The recording for the mine 8th preferably extends through the entire sleeve 2 in the direction of its longitudinal axis L through, ie the sleeve 2 forms as a semi-finished a tube. This simplifies mine casting. Because the sleeve can be placed on the side on which it forms the cone described in more detail below, for the purpose of mine casting in a tightly closing form, which then equal to the end of the mine in the cone an attractive, usually also conical tapered shape there. The lead mass is then poured from the other end of the sleeve, where the seat is located, and fills the lead receptacle in the sleeve 2 off and the mold cavity, which is the top of the mine 8th maps. A plastic sleeve, such as the invention, can be particularly well in a tightly closing form insert for the purpose of mine pouring, since the plastic of the sleeve, as compared with a wooden sleeve, is reversibly elastic, so sealing a corresponding shape can be inserted or spread. The very smooth outer surface of the sleeve contributes to your, to achieve a secure seal.

The one end of the pen 1 tips to a cone 12 to, preferably with a cone angle pi between 20 ° and 60 °. This end contributes in this way to the well-known from a normal wooden pin pointed side so as to form a lug which is positioned correctly at the first sharpening against the sharpener blade and allows the sharpener blade on whole Length to take a chip.

The other end of the pen 1 preferably has a seat 9 in the form of a retracted at its outer diameter area. On this seat can be an end cap 10 be plugged, preferably there is a locking between the seat 9 and the end cap 10 , To preserve the mine as well as possible and avoid migration, an additional seal is usually provided under the cap, often in the form of a plug or silicone plug 11 , The finished pen 1 will be on the page on which the mine 8th over the sleeve 2 stands out, usually with the aid of an attached cap 12 kept fresh. The inventively achieved, very smooth and scratch-resistant outer surface makes the good and safe attachment of the cap 10 Feed. The surface achieved according to the invention is scratch-resistant so that even after 30 times peeling off and reattaching the cap 10 no dulling of the cap visible to the naked eye 10 Run over surface results from extending in the direction of the longitudinal axis of the pin micro-scratch and the like. The cap 10 is performed with some undersize, so a slightly smaller inner diameter, compared with the outer diameter of the sleeve 2 , The cap made in this way 10 can be applied to the surface of the sleeve achieved according to the invention 2 suck on and pull off from there due to their smooth texture (no stick / panties).

Final remarks of a general nature

Independent protection, possibly also enriched with further features from the aforementioned description and / or the existing claims, is claimed for a pen for applying a color and / or cosmetic substance, with a mine from the substance to be applied and the mine ummantelnden, integrally injection-molded sleeve made of a thermoplastic material, which consists of a mixture of a first and a second plastic, and which is characterized in that after cutting the outer peripheral surface such that a chip protrudes from the outer peripheral surface, by mere pulling on the chip, a skin can be pulled off the surface of the sleeve.

Independent protection, possibly also enriched with further features from the aforementioned description and / or the existing claims, is claimed for a pen for applying a color and / or cosmetic substance, with a mine from the substance to be applied and the mine ummantelnden, integrally injection-molded sleeve of a thermoplastic material consisting of a mixture of a first and a second plastic, and which is characterized in that its sleeve has a structure of two manually separable layers, preferably the near-surface of these two layers thinner is.

Independent protection, possibly enriched with further features from the above description, is for a pen for applying a color and / or cosmetic substance, with a mine from the substance to be applied and a mine-jacketing, integrally injection-molded sleeve made of a thermoplastic material, which consists of a mixture of a first and a second plastic, and which is characterized in that its sleeve, viewed in the radial direction, has an outer enrichment zone with a higher concentration of the first plastic than in the central region.

It should be noted that the formation of an inner enrichment zone may possibly be achieved by a corresponding temperature control on the inner circumference of the sleeve. Where this claim comes into force, the above statements apply mutatis mutandis, only special restrictions that are due to the (not available in this variant or purely optional) internal enrichment zone omitted.

Independent protection, possibly also enriched with further features from the aforementioned description and / or the existing claims, is for a pen for applying a color and / or cosmetic substance, with a mine from the substance to be applied and a mine ummantelnden, in one piece injection-molded sleeve of a thermoplastic material, which consists of a mixture of a first and a second plastic, which is characterized in that its sleeve, viewed in the radial direction, an inner enrichment zone with a higher concentration of the first plastic, as in the central region.

It should be noted that the formation of an outer enrichment zone can optionally be achieved by a corresponding temperature control on the outer circumference of the sleeve, the heat energy, which is no longer required after injection into the cavity, is then removed from the plastic mass of the sleeve essentially via its inner circumferential surface. Where this claim comes into force, the above statements apply mutatis mutandis, only special restrictions that are due to the (not available in this variant or purely optional) outer enrichment zone, omitted.

LIST OF REFERENCE NUMBERS

1

pen

2

shell

3

Cross section of the sleeve

4

outer periphery

5

inner circumference

6

Outside enrichment zone

7

Interior enrichment zone

8th

mine

9

Seat

10

end cap

11

Silicone plugs

12

cone

100

measuring point 1

200

Measuring point 2

L

Longitudinal axis of the pin and its sleeve

S

chip

D

Thickness of the skin

A

off length

pi

cone angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2834479 [0009]
• DE 3137486 Al [0010]
• EP 0613634 B1 [0011]
• US 5360281 [0015]
• US 2013/0121747 A1 [0016]

Claims (19)

A pen for applying a color and / or cosmetic substance, comprising a refill of the substance to be applied and a refill molding, integrally injection molded sleeve of a thermoplastic material, which consists of a mixture of a first and a second plastic, characterized in that Cutting the outer circumferential surface so that a chip protrudes from the outer peripheral surface, a skin can be pulled off from the surface of the sleeve by pulling on the chip by hand. Especially after Claim 1 , for applying a color and / or cosmetic substance, with a mine of the substance to be applied and a mine einmantelnden, integrally injection molded sleeve of a thermoplastic material, which consists of a mixture of a first and a second plastic, characterized in that the Sleeve, each seen in the radial direction, an outer enrichment zone having a higher concentration of the first plastic, as in the central region. Pen after Claim 2 , characterized in that the sleeve, each viewed in the radial direction, having an inner enrichment zone with a concentration of the first plastic, as in the center region, wherein the concentration of the first plastic from the outer enrichment zone and from the inner enrichment zone to the center decreases continuously. A pencil according to any one of the preceding claims, characterized in that the plastic sleeve is formed over at least 80%, more preferably at least 90%, of its cross-sectional area both from the first and the second plastic, wherein the two plastics are found in locally different Gew.-shares , A pencil according to the preceding claims, characterized in that the sleeve predominantly, at least 85%, or preferably exclusively, consists of the first and the second plastic, plus any fillers and auxiliaries, such as pigments. A pencil according to any one of the preceding claims, characterized in that a plastic and preferably the first plastic is a weakly polar plastic having an electronegativity difference ΔEN in the range between 0.3 and 0.5 inclusive. A pencil according to one of the preceding claims, characterized in that a plastic and preferably the second plastic is a strongly polar plastic having an electronegativity difference ΔEN in the range between more than 0.5 and 1.7. Pen according to one of the preceding claims, characterized in that the first plastic is an AES or preferably a SAN. Pen according to one of the preceding claims, characterized in that the second plastic is a TPE or preferably a TPC-ET. Pin according to one of the preceding claims, characterized in that the material forming the sleeve material is adjusted so that the first plastic has a weight fraction of at least 45 wt .-%, better at least 55%. A pencil according to any one of the preceding claims, characterized in that the upper limit for the first plastic in the mixture ready for injection is 85% by weight, more preferably 70% by weight. Pin according to one of the preceding claims, characterized in that the sleeve has on the outer peripheral surface an arithmetic average gloss level GU of more than 30 GU, better more than 40 GU. Pin preferably according to one of the preceding claims, characterized in that the sleeve has a structure of two separable layers, wherein preferably the near-surface of these two layers is thinner. Pin according to one of the preceding claims, characterized in that the plastic sleeve consists of a non-foamed plastic. Pin according to one of the preceding claims, characterized in that the sleeve is designed as a tube open at both ends. Pin according to one of the preceding claims, characterized in that the sleeve tapers conically at a front end, preferably with a cone angle (Pi) of 25 ° to 35 ° to the longitudinal axis L of the sleeve. Pin according to one of the preceding claims, characterized in that the sleeve has a shoulder at a front end with a reduced diameter. Pen after Claim 11 , characterized in that at the pin end and preferably on the heel an end cap is attached, which closes one end of the sleeve. Use a sleeve according to Claim 1 or according to one of Claims 2 to 7 for producing a lead pencil, in particular a cosmetic pencil.

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