JP6414300B2 - Structure with liquid layer on the surface - Google Patents

Description

  The present invention relates to a structure having a liquid layer formed on the surface.

  Plastic containers are widely used in various applications because they are easy to mold and can be manufactured at low cost. In particular, a bottle-shaped olefin resin container in which the inner surface of the container wall is formed of an olefin resin such as low density polyethylene and is formed by direct blow molding is a viscous material such as ketchup from the viewpoint that the contents can be easily squeezed out. It is suitably used as a container for containing slurry-like or paste-like contents.

  For bottles containing viscous contents, the bottles may be stored in an inverted state so that the contents can be discharged quickly or used up to the end without remaining in the bottle. There are many. Therefore, when the bottle is turned upside down, there is a demand for the characteristic that the viscous contents do not remain attached to the inner wall surface of the bottle and fall quickly.

As a bottle satisfying such requirements, for example, Patent Document 1 proposes a bottle having a multilayer structure in which an innermost layer is made of an olefin resin having an MFR (melt flow rate) of 10 g / 10 min or more.
In this multi-layered bottle, the innermost layer has excellent wettability to oily contents. As a result, when the bottle is inverted or tilted, the oily contents such as mayonnaise spread along the innermost surface. However, it can be discharged neatly without dropping and remaining attached to the inner wall surface of the bottle (the innermost layer surface).

  In addition, regarding a bottle for viscous non-oil content in which plant fibers such as ketchup are dispersed in water, Patent Document 2 or Patent Document 3 describes a saturated or unsaturated aliphatic amide as a lubricant in the innermost layer. There has been proposed a polyolefin resin bottle in which is blended.

  Patent Documents 1 to 3 mentioned above all improve the slipperiness with respect to the contents by the chemical composition of the thermoplastic resin composition forming the inner surface of the plastic container, and a certain degree of slipperiness improvement is achieved. However, since the types and additives of the thermoplastic resin to be used are limited, there is a limit in improving the slipperiness, and the fact is that a dramatic improvement has not been achieved.

From this viewpoint, recently, improvement of slipperiness has also been studied from a physical viewpoint.
For example, Patent Document 4 proposes a container in which hydrophobic oxide fine particles having an average primary particle diameter of 3 to 100 nm are attached to the inner surface.
Patent Document 5 discloses a water-repellent film having a structure in which oxide fine particles having an average particle diameter of 5 nm to 100 nm are dispersed and adhered to the surface of a resin film formed of resin particles having an average particle diameter of 1 μm to 20 μm. A lid formed on the surface has been proposed.

In any of the technologies proposed in Patent Document 5, fine irregularities are formed on the surface in contact with the contents, and water repellency (hydrophobicity) is expressed by the fine irregular surfaces. That is, in addition to the hydrophobicity of the material forming the uneven surface, an air layer is formed in the voids existing on the uneven surface, and this air layer has a higher water repellency than the material forming the container. The non-adhesiveness to the contents is improved.
However, when such a fine uneven surface is formed, the non-adhesiveness to the aqueous content is improved, but when the content is always in contact with the fine uneven surface, moisture in the concave portion of the fine uneven surface Condensation is very easy to occur, and there is a problem that the slipperiness is deteriorated because the concave portion is filled by moisture condensation, and further improvement of the slipperiness is demanded.

In addition, the present inventors have proposed a plastic container or a resin structure having a liquid layer formed on the surface (for example, WO2014 / 010534 , WO2014 / 123217 , WO2014 / 175378 , WO2014 / 18883 ).
That is, all of these have succeeded in significantly improving the slipperiness with respect to the contents by forming a liquid layer that is immiscible with the contents as compared with the conventionally known ones. By inverting or tilting, the contents can be quickly discharged out of the container without adhering to or remaining on the inner wall of the container.
Thus, the molded body having a structure in which a liquid layer is formed on the surface is applicable not only to the shape of the container but also to a molded body having a form such as a film. These properties can be greatly modified.
However, regarding resin structures such as plastic containers having a liquid layer on the surface, sufficient analysis has not yet been performed, and the surface properties can be greatly improved when the liquid layer is formed in any form. Moreover, whether it can be stably improved has not been fully elucidated, and for this reason, various improvements are currently being made.

JP 2007-284066 A JP 2008-222291 A JP 2009-214914 A JP 2010-254377 A Japanese Patent No. 4878650

  Accordingly, an object of the present invention is a structure in which a liquid layer is formed on the surface of the molded body and a fluid is present on the surface of the liquid layer. The object of the present invention is to provide a structure whose properties are stably improved by a liquid layer.

  As a result of conducting many experiments on slipperiness with respect to a viscous substance with respect to the structure in which the liquid layer is formed on the surface of the molded body, the present inventors have found that the liquid layer is projected so that the liquid surface protrudes locally. When forming the film, the inventors have found that a slipperiness superior to that obtained when the liquid layer is formed so as to have a flat liquid surface, and have completed the present invention.

That is, according to the present invention, in a structure comprising a molded body having a liquid layer on the surface, and a fluid is present on the liquid layer,
The surface supporting the liquid layer is formed with a locally protruding portion, and a portion protruding locally on the surface of the liquid layer corresponding to the protruding portion. Formed,
On the surface of the liquid layer, fine protrusions having a height of 0.7 μm or more are distributed at a density of 20 to 100 pieces / mm ^{2 and} are observed at an average interval of 100 to 300 μm. A structure is provided.

In the structure of the present invention,
(1) The liquid layer is present on the surface of the molded body in an amount of 0.5 to 30 g / m ² .
(2) The surface supporting the liquid layer is made of resin.
(3) The resin forming the surface supporting the liquid layer is an olefin resin or a polyester resin,
(4) The molded body has the form of a container,
Is preferred.

  In the present invention, the surface of the liquid layer protrudes locally means that the surface of the liquid layer (that is, the liquid surface) is not flat, and a convex portion (liquid protrusion) formed by the liquid forming the liquid layer. Part) is formed, and the surface of the underlying resin supporting the liquid layer is not exposed in such a liquid convex part. Such a liquid convex portion is not formed by the movement of the liquid like a wave, but is stably present at a certain position, such as an atomic force microscope, a laser microscope or a white interference microscope. Etc. can be confirmed.

In the structure of the present invention, since a liquid layer is formed on the surface, various surface characteristics can be expressed in the multilayer structure by this liquid layer. Since the portion (liquid convex portion) is formed, the effect of improving the surface characteristics is particularly remarkable.
For example, when formed with an oleaginous liquid such as a fluorinated liquid, a fluorinated surfactant, silicone oil or vegetable oil, the slipperiness and non-adhesiveness to aqueous substances such as water can be greatly improved. However, as shown in the experimental results of Examples and Comparative Examples described later, the sliding speed of mayonnaise when the liquid convex portion is formed is higher than that when the liquid convex portion is not formed. It can be seen that the improvement is about twice as much. Similarly, in the present invention, when the liquid layer is formed of an oil-repellent liquid, the slipperiness and non-adhesiveness with respect to the oily substance can be greatly improved.

  Further, in the present invention, a liquid diffusion preventing layer that suppresses or blocks the diffusion of the liquid forming the liquid layer is provided below the surface resin layer of the molded body supporting the liquid layer. The layer can be stably held over a long period of time, and the surface modification effect can be exhibited over a long period of time.

  Such a structure of the present invention can be applied to various applications by forming a liquid layer with an appropriate liquid by taking advantage of its surface improvement characteristics, but is particularly viscous liquid (for example, ketchup, mayonnaise) , Dressing, etc.) are suitably used as packaging containers.

The figure which shows the form of the surface which is the principal part of the structure of this invention. The figure for demonstrating the principle of this invention. The figure which shows an example of the laminated constitution of the multilayer structure provided with the structure of this invention. The figure which shows an example of the laminated constitution of the multilayer structure provided with the structure of this invention. It is a figure which shows the result of having observed the surface of the resin molding of Example 1 using the scanning white interference microscope, and is a figure which shows the three-dimensional image of the surface. It is a figure which shows the result of having observed the surface of the resin molding of Example 1 using the scanning white interference microscope, and is a figure which shows the shape profile in a cross section. It is a figure which shows the result of having observed the surface of the resin molding of the comparative example 1 using the scanning white interference microscope, and is a figure which shows the three-dimensional image of the surface. It is a figure which shows the result of having observed the surface of the resin molding of the comparative example 1 using the scanning white interference microscope, and is a figure which shows the shape profile in a cross section.

<Surface morphology of resin structure>
Referring to FIG. 1, a resin structure (indicated by 10 as a whole) of the present invention is formed of a resin molded body 1 and a liquid layer 3 covering the surface of the resin molded body 1. However, a particularly important feature is that the liquid protrusions 3a are formed on the surface of the liquid layer 3, and a flat surface 3b is formed between the liquid protrusions 3a. That is, as can be understood from FIG. 1, the surface of the resin molded body 1 is mixed with relatively large protrusions 1a and relatively small protrusions 1b, but the surface of the liquid layer 3 is roughly speaking. The projections 1a and 1b have a shape along the surface of the resin molded body 1, and the liquid projections 3a are formed corresponding to the relatively large projections 1a, and the flat surface 3b. This part covers a relatively small protrusion 1b.

When the liquid layer 3 is formed on the surface, it may be said that the liquid level is flat. For example, when the liquid layer 3 is formed on a surface where the protrusions 1a and 1b are mixed, the protrusion 1a, The liquid layer 3 is formed so as to cover all of 1b, or the relatively high protrusion 1a is exposed, but the liquid layer 3 is formed so as to cover the relatively low protrusion 1b. In general, the surface (liquid surface) 3 is a flat surface. However, in the present invention, not only the surface of the liquid layer 3 is flat, but also the liquid convex portions 3a are formed, which is extremely specific.
In the present invention, excellent slipperiness can be expressed by such a specific surface shape of the liquid layer 3.

Referring to FIG. 2 for explaining the principle of the present invention, when surface properties such as slipperiness of the surface of the resin molded body 1 with respect to the fluid 5 are improved by the liquid layer 3, conventionally, FIG. As shown in FIG. 4, the fluid 5 is brought into full contact with the surface of the liquid layer 3, so that the surface characteristics can be improved by selecting the type of liquid that forms the liquid layer 3 according to the material of the fluid 5. It is a big improvement. That is, the surface properties of the fluid 5 are improved by the property of the liquid forming the liquid layer 3 with respect to the fluid 5.
However, in the present invention, as shown in FIG. 2B, when the fluid 5 slides on the resin molded body 1, the fluid 5 contacts the liquid layer 3 but does not come into full contact. Then, the liquid convex portion 3a is partly formed so as to partially come into contact with the liquid layer 3 and slide. That is, in the present invention, the liquid convex portion 3a is formed on the surface of the liquid layer 3, and the fluid 5 and the liquid layer 3 partially slide in contact with each other, as shown in FIG. Compared with the case where the liquid 5 and the liquid layer 3 slide in contact with each other, the slipperiness with respect to the fluid 5 is further greatly improved.

As described above, the reason why the fluid 5 and the liquid layer 3 partially slip and come into contact with each other does not completely elucidate the reason why the slipperiness is further improved. It is estimated that.
That is, since the flow of the fluid 5 when the fluid 5 slides on the surface of the liquid layer 3 corresponds to a Couette flow in which the flow velocity has a linear distribution, the frictional force F received by the fluid 5 from the liquid layer 3 is expressed by the following equation: ;
F = ηVA / h
Where η is the viscosity of the liquid forming the liquid layer 3,
V is the flow velocity V of the fluid 5,
A is the contact area between the fluid 5 and the liquid layer 3;
h is the thickness of the liquid layer 3;
It is represented by
When the frictional force F is compared between the flow of the fluid 5 in the case of FIG. 2A and the flow in the case of FIG. 2B, the contact area is significantly more in the case of the flow of FIG. It is understood that the friction force F is considerably smaller in the flow of FIG. 2B, since the friction force F is smaller (η is due to the type of liquid and is the same). That is, by forming the liquid convex portion 3a on the surface of the liquid layer 3 as in the present invention, the frictional force F against the sliding of the fluid 5 is extremely small. As a result, the sliding speed becomes extremely large, It is estimated that the slipperiness is greatly improved. In short, in the case of FIG. 2A, the slipperiness is improved only by the chemical property of the liquid forming the liquid layer 3, but in the present invention, the friction due to the reduction of the contact area is added in addition to the chemical property of the liquid. Since the physical action of force reduction is also added, further improvement in slipperiness can be obtained.

  By the way, when considering the effect of improving the slipperiness according to the present invention, it is conceivable that the slipperiness is improved by entraining air between the fluid 5 and the liquid layer 3. However, the liquid protrusion 3a formed on the surface of the liquid layer 3 is extremely fine and short (the height difference Δh from the flat surface 3b is small). For this reason, it is not considered that a large space that entrains air between the fluid 5 and the liquid layer 3 is formed. Therefore, as described above, the frictional force F is reduced, so that the slipping property is reduced. It is reasonable to think that

  The surface structure of the resin structure of the present invention described above can be analyzed by an atomic force microscope, a laser microscope, a white interference microscope, or the like, as described in the examples described later. This can be easily confirmed by measuring the contact angle (WCA).

According to the analysis of such a surface structure, in the present invention, the surface of the liquid layer 3 has 20 to 100 pieces / mm ² of liquid protrusions 3a (fine protrusions) having a height Δh of 0.7 μm or more. It is desirable to be distributed by density, and further, it is desirable to observe at an interval (L) of 100 to 300 μm on average. The height Δh of the liquid convex portion 3a is a difference in height between the convex portion 3a and the flat surface 3b.
That is, when the interval (L) between the liquid convex portions 3a having the height as described above is narrower than the above range (the liquid convex portions 3a are formed densely), the liquid layer 3 when the fluid 5 slides down and Therefore, the frictional force F cannot be reduced, and the effect of improving slipperiness tends to be reduced. Further, when the interval L between the liquid convex portions 3a is larger than the above range (the liquid convex portions 3a are formed sparsely), the contact area with the liquid layer 3 when the fluid 5 slides down becomes large. End up. This is because the space between the liquid convex portions 3a is widened, and naturally, the fluid 5 and the liquid layer 3 are brought into contact with each other even on the flat surface 3b. In particular, when the fluid 5 is a viscous fluid, the shape of the fluid 5 changes, so the tendency of increasing the contact area is particularly remarkable. Therefore, also in this case, the reduction of the frictional force F cannot be expected, and the effect of improving the slipperiness becomes small.
Further, even if the liquid convex portion 3a is formed so as to satisfy the interval L as described above, if the height Δh is lower than the above range, the liquid layer when the fluid 5 slides down is again. 3 is increased, the frictional force F cannot be reduced, and the effect of improving slipperiness is reduced.

  There is a limit to the height difference Δh of the liquid convex portion 3a as described above, and the upper limit is usually about 50 to 100 μm. That is, the projection 1a having a large height can be formed on the surface of the resin molded body 1 supporting the liquid layer 3, but when the liquid layer 3 is formed on the projection 1a having such a height, This is because the amount of liquid forming the liquid layer 3 must be increased, and as a result, almost the entire surface of the liquid layer 3 becomes a flat surface 3b, and a large height difference Δh cannot be realized. .

In the present invention described above, the liquid layer 3 is quite thin. For example, the amount of liquid forming the liquid layer 3 is 0.5 to 30 g / m ² , particularly 0.5 to 20 g / m ² , especially 0. It is preferably in the range of 5 to 10 g / m ² . That is, if the amount of the liquid is small, the liquid layer 3 becomes a discontinuous layer, and it becomes difficult to make full use of the chemical properties (for example, water repellency and oil repellency) of the liquid to the fluid 5. It becomes difficult to obtain the effect of improving slipperiness. On the other hand, when the amount of liquid is too large, the height Δh of the liquid convex portion 3a becomes small, and as a result, the reduction of the frictional force F due to the reduction of the contact area becomes insufficient, and a large slip improvement effect is obtained. Becomes difficult.

Further, in the present invention, the liquid layer 3 described above has the following formula (1) in order to stably and uniformly impart surface characteristics due to the liquid:
F = (cos θ−cos θ _B ) / (cos θ _A −cos θ _B ) (1)
Where
θ is a water contact angle on the surface of the resin structure 10,
θ _A is a water contact angle on the liquid forming the liquid layer 3,
θ _B is a water contact angle on a single plastic that forms the resin molded body 1.
The coverage F of the liquid layer 3 calculated in step (1) should be 0.5 or more, preferably 0.6 or more. That is, when the water contact angle θ on the surface of the resin structure 10 and the water contact angle water θ _A on the liquid layer 3 are the same, the coverage F is 1.0 and the resin molding 1 The whole is covered with the liquid layer 3.
For example, if the coverage F is smaller than the above range, the liquid layer 3 is formed in such a form that the liquid is scattered on the surface even if the liquid amount is large, and it is difficult to exhibit sufficient surface characteristics. End up.

Here, the above-described equation (1) is obtained by modifying the Cassie-Baxter equation that expresses the apparent contact angle θ on the composite surface whose surface is formed from two types of components (A, B). This is expressed by the following equation.
cos θ = F _A cos θ _A + F _B cos θ _B
= F _A cos θ _A + (1−F _A ) cos θ _B
Where
F _A indicates the proportion of the A component,
F _B represents the ratio of the B component (where F _A + F _B = 1),
θ _A represents the contact angle of the liquid on the component A alone, and θ _B represents the contact angle of the liquid on the component B alone.

  In the present invention, the surface of the resin molded body 1 supporting the liquid layer 3 (hereinafter referred to as a base surface) in relation to the formation of the liquid protrusion 3a described above on the surface of the liquid layer 3. ) Includes a relatively large protrusion 1a and a relatively small protrusion 1b. As described above, the liquid protrusion 3a is formed corresponding to the relatively large protrusion 1a and is relatively small. A flat surface 3b of the liquid layer 3 is formed on the protrusion 1b. Such protrusions 1a and 1b can also be analyzed by an atomic force microscope, a laser microscope, a white interference microscope, or the like.

For example, in a three-dimensional surface shape profile of the surface of the resin molded body 1 obtained by scanning a range of 1.4 mm × 1.05 mm with a white interference microscope, the density of protrusions having a height of 0.7 μm or more is 20 to 100 / mm. ^In addition, the distance (L) between the protrusions is preferably in the range of 100 to 300 μm on average. Further, the maximum protrusion height of such protrusions is in the range of 1.5 to 40 μm, particularly 2.5 to 30 μm, so that the liquid layer 3 can be stably held over the entire ground surface and can satisfy the above-described conditions. It is preferable for forming the convex portion 3a. That is, when the projection density is smaller than the above range and the maximum projection height is smaller than the above range, the projection interval L becomes large and the large projection 1a corresponding to the liquid convex portion 3a is not formed, and the above-described liquid state The formation of the convex portion 3a becomes difficult, the contact area with the flat surface 3b becomes large, and the effect of the present invention is not exhibited. Further, when the protrusion density is larger than the above range, the protrusion interval L is small, and although depending on the coating amount of the liquid layer, the liquid tends to fill the space between the protrusions. The portion 3a is not formed, the contact area with the flat surface 3b is increased, and the effects of the present invention may not be exhibited.

<Formation of surface structure>
In the present invention, the above-described surface structure of the resin structure 10 includes a resin for forming the resin molded body 1 (underlying surface) and a surface roughening additive and a liquid for forming the liquid layer 3. And it can implement | achieve by forming the surface (base surface) of the resin molding 1 by shaping | molding using such a resin composition.

The resin for forming the resin molded body 1 (base surface) is not particularly limited as long as it can be molded into a shape according to the use of the resin structure 10, and any resin can be used. In particular, a thermoplastic resin having a relatively low density (for example, about 1.7 g / cm ³ or less) is preferable in that the liquid layer 3 can be formed by liquid leaching. Olefin resins such as density polyethylene, medium or high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, copolymer resins of these olefins, polyethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate / Polyester resins such as isophthalate are preferred. In particular, when this resin structure 10 is used as a squeeze container for squeezing the contents, it is preferable to use an olefin resin typified by low density polyethylene or linear low density polyethylene.

The surface roughening additive blended in the above resin is used to make the surface of the base surface a rough surface having the above-described protrusion density (1 / mm ² ) and maximum protrusion height within a predetermined range. Usually, fine particles having an average particle diameter of 40 μm or less, particularly 0.2 to 20 μm are used. For example, among the fine particles in the above range, inorganic fine particles such as silica are very small fine particles having a primary particle diameter of 0.003 to 0.2 μm as a structural unit of the particles, and there is a strong attractive force between the primary particles. Since it works, it cannot exist alone as the primary particle diameter, and is usually present in the form of secondary particles that are aggregated and have a high specific surface area and a large pore volume. For this reason, when such fine particles are blended with a resin and molded, the projections 1a and 1b in which these fine particles are continuous are formed, and the projections formed by the fine particles retain liquid. For example, the liquid layer 3 can be formed on the tall and large protrusion 1 a, and the liquid protrusion 3 a can be easily formed on the surface of the liquid layer 3.
The average particle size of the fine particles varies depending on the type and size of the fine particles, but in general, a method using an electron microscope such as a transmission electron microscope or a scanning electron microscope, or a laser diffraction particle size distribution measurement. It can be measured by a laser diffraction / scattering method using an apparatus. The average particle size of the fine particles is defined as the average particle size measured in the observation by an electron microscope, and in the measurement by the laser diffraction / scattering method, the integrated value in terms of volume in the obtained particle size distribution is 50%. Is defined as the particle size. In addition, in the fine particles having a primary particle size of 0.2 μm or less such as silica, it is extremely difficult to make the primary particles alone, so the particle size of the secondary particles is defined as the average particle size.

  The fine particles as described above are not particularly limited as long as the average particle diameter is in the above range. In general, for example, metal oxide particles such as titanium oxide, alumina and silica, carbonates such as calcium carbonate, carbon Typical are carbon fine particles such as black, organic fine particles composed of polymethyl (meth) acrylate, silicone particles such as polyethylene and polyorganosilsesquioxane, and these include silane coupling agents and silicone oils. May be hydrophobized. In the present invention, since it can be carried out also by extrusion molding typified by direct blow molding, it is only necessary to maintain the particle diameter after melt molding. For example, fine particles that have been hydrophobized, particularly hydrophobic silica, polymethyl A methacrylate cured product, ultrahigh molecular weight polyethylene, polyorganosilsesquioxane, and silicone particles are preferably used.

  The fine particles used as the roughening additive are usually 0.1 to 30 parts by weight, preferably 0.3 to 20 parts by weight, more preferably 0.3 to 10 parts by weight per 100 parts by weight of the resin. Used in parts by weight. When the amount used is outside this range, it is difficult to form a rough surface that can suitably form the liquid convex portion 3a.

  Furthermore, as the liquid used for forming the liquid layer 3, an appropriate one is used according to the surface characteristics to be applied to the surface of the resin structure (resin molded body 1). Of course, it must be a non-volatile liquid having a low vapor pressure under atmospheric pressure, for example, a high-boiling liquid having a boiling point of 200 ° C. or higher. This is because when a volatile liquid is used, it easily evaporates and disappears with time, and it becomes difficult to form the liquid layer 3.

  Specific examples of such a liquid include various liquids provided that the liquid is a high-boiling liquid as described above. In particular, the surface tension is significantly different from a material to be slidable. The higher the lubrication effect, the better the present invention. For example, in order to improve the slipperiness with respect to water or a hydrophilic substance containing water, it is preferable to use a liquid having a surface tension of 10 to 40 mN / m, particularly 16 to 35 mN / m. Typical examples include surfactants, silicone oils, fatty acid triglycerides, and various vegetable oils. Suitable vegetable oils include soybean oil, rapeseed oil, olive oil, rice oil, corn oil, bean flower oil, sesame oil, palm oil, castor oil, avocado oil, coconut oil, almond oil, walnut oil, sandwich oil, salad oil, etc. Can be used for

  This liquid is generally used in an amount of 0.3 to 20 parts by weight, in particular 1 to 10 parts by weight, per 100 parts by weight of the aforementioned resin. If the amount is small, the formation of the liquid layer 3 becomes difficult. If the amount is too large, the liquid layer 3 can be formed even if the liquid layer 3 can be formed. It becomes difficult to form on the surface.

The resin structure 10 of the present invention uses a resin composition prepared by mixing the above-described resin, the surface roughening additive, and the liquid layer forming liquid, such as extrusion molding and direct blow molding. It can be produced by molding into a predetermined shape by means known per se. Also, a coating solution in which the above resin composition is dissolved or dispersed is prepared using an appropriate low boiling point organic solvent (for example, a hydrocarbon solvent or an alcohol solvent), and the coating solution is molded into a predetermined shape in advance. It can also be produced by means of coating on a formed molded body and drying.
In this way, the liquid oozes onto the lower ground of the appropriately roughened resin molded body 1, and the liquid layer 3 having the liquid convex portions 3a on the surface is formed.

Although a method of making the surface of the resin molded body 1 an appropriate rough surface by machining such as laser processing or sand blasting can be considered, the surface roughness suitable for forming the liquid convex portion 3a is quite fine. Therefore, it is not suitable for formation by machining, and it is preferable to use a resin composition in which fine particles are internally added as an additive for roughening as described above.
Further, although a method of forming the liquid layer 3 by externally adding a liquid forming the liquid layer 3 by a method such as spraying or dipping is also conceivable, the liquid layer 3 having the liquid protrusions 3a is a fairly thin layer, Such a method of externally adding a liquid is not suitable, and the liquid layer 3 may be formed by using a resin composition having a liquid internally added.

<Multilayer structure>
Although the resin structure 10 of the present invention having the above-described surface structure can be used alone as it is, it is usually a multilayer structure in which layers made of other materials are laminated while leaving this surface structure. It is preferable to use it. For example, it is preferable to employ a multilayer structure in which a liquid diffusion prevention layer is provided on the lower side of the resin molded body forming the base surface that supports the liquid layer 3.

For example, in the example of FIG. 3, the overall structure indicated by 30 has a base resin layer 1 ′ having the liquid layer 3 having the liquid convex portion 3 a (not shown in FIG. 3) on the surface. The base resin layer 1 ′ is laminated on the liquid diffusion preventing layer 20, and the liquid diffusion preventing layer 20 is provided on a base material 23 made of an appropriate material.
That is, the base resin layer 1 ′ corresponds to the resin molded body 1 described above, and the combination of the base resin layer 1 ′ and the liquid layer 3 corresponds to the resin structure 10 of FIG.

In the layer structure of FIG. 3, the liquid diffusion preventing layer 20 blocks penetration and diffusion of the liquid forming the liquid layer 3, and is provided by the liquid layer 3 by forming such a layer. Surface characteristics will be maintained stably over a long period of time.
That is, even if a certain amount of liquid is blended in the base resin layer 1 ′ and the liquid layer 3 is formed by the exudation of this liquid, the liquid gradually spreads on the surface opposite to the base resin layer 1 ′. Since it moves, the amount of liquid forming the liquid layer 3 decreases with time, and as a result, the surface properties imparted to the liquid layer 3 may be lost with time. However, in the embodiment of FIG. 3, since the penetration and diffusion of the liquid from the liquid layer 3 (or the base resin layer 1 ′) is blocked by the presence of the liquid diffusion preventing layer 20, it is effective to reduce the liquid volume of the liquid layer 3. It is possible to avoid the loss of surface characteristics over time.

  The material of the liquid diffusion preventing layer 20 is not particularly limited as long as it can prevent the permeation and diffusion of the liquid. For example, the liquid diffusion preventing layer 20 is made of a metal foil, a metal vapor deposition film, or an inorganic material such as glass or ceramics. Alternatively, it may be formed from an organic material such as a diamond-like carbon (DLC) vapor-deposited film, a thermosetting resin or a thermoplastic resin, but when it is formed from an inorganic material, the molding means is limited, Since the form of the multilayer structure 30 or the base resin layer 1 ′ is limited to a film or the like, it is generally preferable that the multilayer structure 30 or the base resin layer 1 ′ be formed of an organic material, particularly a thermoplastic resin. That is, the thermoplastic resin is excellent in moldability, and the form of the multilayer structure 30 is not limited. For example, a form such as a blow molded container can be adopted.

The thermoplastic resin for forming the liquid diffusion preventing layer 20 as described above has a density of 1.00 g / cm ³ or more and a glass transition point (Tg) of 35 ° C. or higher, or a crystallinity degree. The thing of 0.5 or more is used. That is, since such a thermoplastic resin is dense and the movement and diffusion of the liquid in the resin is considered to be extremely limited, the penetration and diffusion of the liquid can be effectively suppressed. For example, in a resin whose density and glass transition point (Tg) are lower than the above ranges, the liquid diffusion prevention layer becomes a loose layer, and the limitation of liquid migration and diffusion is weakened, effectively preventing liquid penetration and diffusion. It becomes difficult. In addition, in a resin having a crystallinity of less than 0.5, since there are few crystal components that restrict the movement and diffusion of liquid in the resin and the restriction is weakened, it is difficult to effectively prevent the permeation and diffusion of the liquid. It becomes.

  The above thermoplastic resin is inferior in liquid diffusion preventing performance compared to inorganic materials such as metal foil, metal vapor deposition film and glass, so the thickness of the liquid diffusion preventing layer 20 needs to be relatively thick. For example, 2 μm As described above, it is particularly preferable to form the liquid diffusion preventing layer 20 with a thickness of about 5 to 80 μm. That is, if this thickness is too thin, the liquid diffusion preventing ability may be unsatisfactory, and even if it is excessively thick, the multilayer structure 30 becomes unnecessarily thick, which is advantageous in terms of cost. Because there is no. The thickness of the liquid diffusion preventing layer 20 can be adjusted according to the required maintenance period of the surface characteristics.

  In the present invention, the thermoplastic resin having the above-described density and glass transition point (Tg) is not particularly limited, but in general, an ethylene / vinyl alcohol copolymer (saponified ethylene / vinyl acetate copolymer). Gas barrier resins such as aromatic polyamide and cyclic polyolefin, polyesters such as polyethylene terephthalate and liquid crystal polymer, and polycarbonate are preferable. For example, when the liquid diffusion preventing layer 20 is formed of such a gas barrier resin, the liquid diffusion preventing layer 20 can be provided with a gas barrier property that prevents permeation of a gas such as oxygen. When the structure 20 is used in such a form, it is possible to prevent oxidative deterioration of the contents, which is extremely advantageous. Among these, an ethylene / vinyl alcohol copolymer is most preferable because it exhibits particularly excellent oxygen barrier properties.

  The ethylene-vinyl alcohol copolymer as described above is generally an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, and a saponification degree of 96 mol% or more. In particular, a saponified copolymer obtained by saponification so as to be 99 mol% or more is suitable. Of these, those having a density and a glass transition point (Tg) in the above-mentioned range are selectively used. It is good to do.

  The gas barrier resins described above can be used alone, respectively, and as long as the density and glass transition point (Tg) are within the above ranges, a polyolefin such as polyethylene and a gas barrier resin are blended. The liquid diffusion preventing layer 20 can also be formed.

  By the way, when the gas barrier resin as described above is used as the liquid diffusion prevention layer 20, the liquid diffusion prevention is performed in order to improve adhesion with the base resin layer 1 ′ (or the base material 23) and prevent delamination. It is preferable to provide an adhesive resin layer (not shown) adjacent to the layer 20. Thereby, the liquid diffusion preventing layer 20 can be firmly bonded and fixed to the base layer resin layer 1 or the base material 23. Adhesive resins used for forming such an adhesive resin layer are known per se. For example, a carbonyl group (> C═O) is 1 to 100 meq / 100 g resin in the main chain or side chain, particularly 10 to 100 meq / 100 g. Resin contained in the amount of resin, specifically, olefin resin graft-modified with carboxylic acid such as maleic acid, itaconic acid, fumaric acid or its anhydride, amide, ester, etc .; ethylene-acrylic acid copolymer; An ion-crosslinked olefin copolymer; an ethylene-vinyl acetate copolymer; and the like are used as the adhesive resin. The thickness of such an adhesive resin layer may be such that an appropriate adhesive force can be obtained, and is generally 0.5 to 20 μm, preferably about 1 to 8 μm.

  Further, when the gas barrier resin as described above is used as the liquid diffusion preventing layer 20 in the form of a film, any adhesive resin may be used, for example, for dry lamination, anchor coating, and primer. Well, although not particularly limited, for example, urethane resin, phenol resin, epoxy resin, alkyd resin, melamine resin, acrylic resin, polyester resin, amino resin, fluororesin, cellulose resin, isocyanate resin, etc., known per se are used. be able to. These adhesive resins may be used alone or may be blended if necessary. Moreover, as long as adhesion and wettability with a base material can be ensured, either water-based or solvent-based can be used. In addition to the above components, as long as the performance as an adhesive is not impaired, a curing acceleration catalyst, a filler, a softening agent, an anti-aging agent, a silane coupling agent, a stabilizer, an adhesion promoter, and leveling are known per se. Agents, antifoaming agents, plasticizers, inorganic fillers, tackifying resins, and the like can also be used. The application amount of these adhesives is not particularly limited as long as it does not impair the paintability and economy, preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.1 to 5.0 μm, For example, it may be applied by spray coating, dipping, or spin coater, bar coater, roll coater, gravure coater or the like.

  Such an adhesive resin usually has the density, glass transition point, and crystallinity in the above-described range, and therefore has a function as the liquid diffusion preventing layer 20. That is, when the liquid diffusion preventing layer 20 described above is formed of a gas barrier resin, the total thickness of the gas barrier resin layer and the adhesive resin layer is within the above-described thickness range (2 μm or more). In particular, by setting the thickness to be about 5 to 80 μm, a sufficient function as the liquid diffusion preventing layer 20 can be exhibited.

  In the present invention, the liquid diffusion prevention layer 20 described above has an interval d from the surface of the base resin layer 1 ′ (interface between the base resin layer 1 ′ and the liquid layer 3) of 200 μm or less, preferably 150 μm or less. It is preferable that it is formed to be in the range. That is, if the distance d is too large, even if the liquid diffusion preventing layer 20 prevents the penetration and diffusion of the liquid, a large amount can exist between the liquid diffusion preventing layer 20 and the surface of the base resin layer 1 ′. As a result, it may be difficult to effectively suppress the formation of the liquid layer 3 and the disappearance of the liquid layer 3 over time.

  Further, as can be understood from the above description, the base resin layer 1 ′ is formed such that the distance d between the surface (interface with the liquid layer 3) and the liquid diffusion preventing layer 20 is a certain value or less. However, in order to develop an appropriate anchor effect for the liquid layer 3, it is preferable that the liquid layer 3 has a thickness of at least 5 μm, particularly 10 μm.

In the multilayer structure of FIG. 3, the base material 23 formed on the other side of the liquid diffusion preventing layer 20 is not particularly necessary, but is appropriately provided according to the usage form of the multilayer structure 30.
The material of the base material 23 is selected according to the usage pattern of the multilayer structure 30, but is generally formed of various plastics, paper, or the like, and may be formed of a plurality of layers. For example, the base material 23 can have a multilayer structure including a resin layer having the same function as the liquid diffusion prevention layer 20 described above. Further, scrap resin such as burrs generated when the structure 30 is molded. A repro layer containing can also be formed in the substrate 23.
That is, when this multilayer structure 30 is used as a squeeze container for squeezing the contents, the base material 23 is formed using low density polyethylene, linear low density polyethylene, or polypropylene from the viewpoint of squeeze properties. In this case, an adhesive resin layer can be provided as appropriate between the base material 23 and the liquid diffusion preventing layer 20, and as described above, the inner layer than the base material 23 (opposite to the liquid layer 3). Further, a gas barrier-resin layer (which also functions as a liquid diffusion preventing layer) and a repro layer can be provided as the side layer.

The layer structure of the structure 20 described above is not limited to the layer structure shown in FIG. 3. For example, as shown in FIG. 4, the layer structure between the base resin layer 1 ′ and the liquid diffusion prevention layer 20 is used. The liquid diffusion adjusting layer 25 can be provided on the substrate.
As already described, the liquid for forming the liquid layer 3 is blended in the base resin layer 1 ′, and the liquid layer 3 is formed by the leaching of the liquid from the base resin layer 1 ′. In the aspect, the liquid penetrates and diffuses also in the liquid diffusion control layer 25, and the amount of the liquid leached on the surface of the base resin layer 1 ′ is adjusted to an appropriate range, so that an excessive amount of liquid oozes out. This is advantageous in preventing the formation of the liquid layer 3 having the liquid convex portions 3a on the liquid surface with an appropriate liquid amount.

  The resin forming the liquid diffusion adjusting layer 25 may be basically any resin as long as the liquid forming the liquid layer 3 can permeate and diffuse, but usually the base resin layer It is formed of the same kind of resin as that forming 1 ′.

Even when the liquid diffusion adjusting layer 25 as described above is provided, the distance d between the liquid diffusion preventing layer 20 and the surface of the base resin layer 1 ′ is preferably in the above-described range. setting the condition that the distance d is maintained, the thickness ratio _t 1 / _{t 2} and the thickness _{t 2} of the thickness _{t 1} and the base resin layer 3 of the liquid diffusion modulating layer 25 is in the range of 0.1 to 10 in It is preferable to sufficiently perform the function of the liquid diffusion control layer 25 .

  In addition, in the range which does not impair the characteristic of each layer according to the kind of material which forms this in the base resin layer 1 'mentioned above, the liquid diffusion prevention layer 20, the liquid diffusion adjustment layer 25, and further the base material 23, Additives such as antioxidants, surfactants, and colorants may be appropriately blended.

  The multilayer structure 30 having the layer structure as described above is different in the type of liquid that forms the liquid layer 3 depending on its form and use, but in order to fully exhibit the surface characteristics of the liquid layer 3, A liquid convex portion 3a is formed on the liquid surface of the liquid layer 3, and the coverage F of the liquid layer 3 represented by the formula (1) is 0.5 or more, particularly 0.6 or more, and is most effective. Is held at 0.8 or more.

<Uses of Resin Structure 10 and Multilayer Structure 30>
The resin structure 10 of the present invention and the multilayer structure 30 on which the resin structure 10 is laminated can have various forms, and a liquid that forms the liquid layer 3 is selected according to the form. The surface characteristics can be exhibited.

For example, the resin structure 10 or the multilayer structure 30 can be used in the form of a film, which is attached to a predetermined place.
In such a case, the surface of the base resin layer 1 ′ of the multilayer structure 30 and the back surface of the liquid diffusion prevention layer 20 (or the base material 23) are appropriately peeled off such as silicon paper or polyester film via an adhesive or the like. A film may be provided, and the release film may be peeled off prior to use and attached to a predetermined surface such that the surface of the base resin layer 1 ′ is exposed. When the multilayer structure 30 of the present invention is used in such a form, the surface characteristics of the liquid layer 3 can be expressed at an arbitrary place. For example, if a fluorosurfactant is used as a liquid for forming the liquid layer 3 and the multilayer structure 30 is attached to a mirror in a bathroom, water droplets do not adhere to the surface of the mirror and quickly flow down. The function as anti-fogging can be exhibited.
The above usage pattern is exactly the same in the single-layer resin structure 10 shown in FIG.

  When the release film is provided on the surface of the base resin layer 1 ′ (resin molded body 1 in FIG. 1), the release resin is peeled off to internally add to the base resin layer 1 ′ (or resin molded body 1). The liquid that has been exuded to the surface will form the liquid layer 3.

The multilayer structure 30 in the form of a film as described above is obtained by using a conventional method such as a casting method, a T-die method, a calendar method, or an inflation method, the base resin layer 1 ′, the liquid diffusion preventing layer 20, and the liquid diffusion adjusting layer 15, Furthermore, it can be formed by forming a film to be the base material 23 and heat-pressing it, or by simultaneously extruding resins forming these layers.
Moreover, it can also be set as a bag-shaped container by affixing two sheets of the film-shaped multilayer structure 30. FIG.
The resin molded body having a single layer structure in FIG. 1 is basically the same.

Moreover, in this invention, it is suitable to use this multilayer structure 30 (or resin structure 10) with the form of a container from a viewpoint of fully utilizing the surface characteristic by the liquid layer 3. FIG. That is, by forming the liquid layer 3 on the inner surface (the surface in contact with the contents) of the container, the contents are prevented from adhering to the container wall, and depending on the form of the container, the contents can be discharged quickly and in a short time. be able to.

  The form of the container is not particularly limited, and may have a form corresponding to the container material, such as a cup or cup shape, a bottle shape, a bag shape (pouch), a syringe shape, an acupoint shape, or a tray shape, and is stretch-molded. May be.

In the packaging container described above, the surface characteristics of the liquid layer 3 can be sufficiently exerted, and in particular, makeup such as ketchup, aqueous paste, honey, various sauces, mayonnaise, mustard, dressing, jam, chocolate syrup, and emulsion. It is most suitable as a container filled with viscous contents such as liquid, liquid detergent, shampoo and rinse. That is, by forming the liquid layer 3 with an appropriate liquid according to the type of contents, the contents can be quickly discharged without being attached to the inner wall of the container by tilting or inverting the container. Because.
For example, ketchup, various sauces, honey, mayonnaise, mustard, jam, chocolate syrup, milky lotion, etc. are hydrophilic substances containing moisture, and the liquid forming the liquid layer 3 includes silicone oil, glycerin fatty acid ester, edible Oily liquids approved as food additives such as oil are preferably used.

The invention is illustrated in the following examples.
In addition, various properties, methods for measuring physical properties, and the like used in the following examples, and resins used for molding the resin structure (container) are as follows.

1. Measurement of Coverage of Liquid Layer A test piece of 10 mm × 60 mm was cut out from the trunk of a multilayer container which is a resin structure having a capacity of 500 g produced by the method described later. Using a solid-liquid interface analysis system DropMaster700 (manufactured by Kyowa Interface Chemical Co., Ltd.) under the condition of 23 ° C. and 50% RH, the test sample was fixed so that the inner layer was on top, and 3 μL of pure water was placed on the test piece. The water contact angle θ was measured. Using the obtained water contact angle, the coverage F of the liquid layer on the surface of the resin structure was determined from the following formula (1).
F = (cos θ−cos θ _B ) / (cos θ _A −cos θ _B ) (1)
In the formula, θ is a water contact angle on the surface of the resin structure,
θ _A is the water contact angle on the liquid forming the liquid layer,
θ _B is a water contact angle on a single plastic forming the resin molding.
In obtaining the liquid layer coverage F, the following water contact angle values were used as the values of θ _A and θ _B.
θ _B : 100.1 °
(Value in the high pressure method low density polyethylene (MFR = 0.3) simple substance forming the resin molding)
θ _A : 80.3 °
(Value on medium chain fatty acid triglyceride (liquid))

2. Measurement of coating amount of liquid layer Using a multi-layer container having a capacity of 500 g produced by the method described later, the liquid layer formed on the inner surface of the container is recovered with 30 mL of a solvent miscible with the liquid layer (heptane), and an evaporator is used. After concentration, the residue was transferred to an evaporating dish and the weight of the liquid layer component was determined. The obtained weight was divided by the area of the inner surface of the container to obtain the liquid layer coating amount (g / m ² ) on the inner surface of the bottle. The smaller this value is, the thinner the liquid layer is formed on the inner surface of the container.

3. Measurement of sliding speed of fluid contents A test piece of 20 mm × 70 mm was cut out from the body of a multilayer container which is a resin structure having a capacity of 500 g produced by the method described later. Using a solid-liquid interface analysis system DropMaster700 (manufactured by Kyowa Interface Chemical Co., Ltd.) under the condition of 23 ° C. and 50% RH, the inner layer of the test piece is fixed so that 70 mg of fluid content is placed on the test piece. On top of that, the sliding behavior at an inclination angle of 45 ° was photographed with a camera, the sliding behavior was analyzed, and the sliding speed was calculated from the movement distance-time plot. This sliding speed was used as an index of sliding ability. The larger the sliding speed value, the better the sliding performance of the contents. The flowable contents used are as follows. In addition, as a viscosity of the contents, a value measured at 25 ° C. using a tuning fork type vibration viscosity system SV-10 (manufactured by A & D Co., Ltd.) is also shown.
Fluid content used;
QP Half KYOPY Co., Ltd. mayonnaise style low calorie food Viscosity = 1260mPa ・ s

4). Measurement of depth / thickness and total thickness of liquid diffusion preventing layer in resin structure Layer structure in body horizontal cross section at position of 50 mm from bottom of multilayer container which is resin structure molded by method described later The depth and thickness of the liquid diffusion preventing layer in the multilayer resin structure and the overall thickness were determined. The configuration at 0 °, 90 °, 180 °, and 270 ° relative to the cross section was observed, and the average value in the four directions was the depth / thickness of the liquid diffusion preventing layer in the multilayer resin structure, and the overall thickness. It was.

5. Measurement of surface shape of resin structure A test piece of 10 mm × 10 mm was cut out from the body of a multilayer container, which was a resin structure having a capacity of 500 g, prepared by the method described later. Image analysis and shape measurement of the surface of the resin structure were performed using a non-contact surface shape measuring machine (NewView 7300, manufactured by zygo).
MetroPro (Ver. 9.1.4 64-bit) was used as an application for image analysis and surface shape measurement.
A range of 1.40 mm × 1.05 mm was measured, and from the obtained raw data, a wavelength of 6.576 μm or less of a high frequency component was cut for noise removal to obtain measurement data. From the measurement data, the projection density (number of projections per 1 mm ² area), average projection spacing, maximum projection height, average projection height, and standard deviation of projection height for projections with a height of 0.7 μm or more Asked.

<Liquid for forming a liquid layer>
Medium chain fatty acid triglyceride (MCT)
Surface tension: 28.8 mN / m (23 ° C.)
Viscosity: 33.8 mPa · s (23 ° C)
Boiling point: 210 ° C or higher Flash point: 242 ° C (reference value)
In addition, the surface tension of the liquid used the value measured at 23 degreeC using the solid-liquid interface analysis system DropMaster700 (made by Kyowa Interface Science Co., Ltd.). Moreover, the density of the liquid required for the liquid surface tension measurement used the value measured at 23 degreeC using the density specific gravity meter DA-130 (made by Kyoto Electronics Industry Co., Ltd.). Furthermore, the viscosity of the liquid showed the value measured at 23 degreeC using the tuning fork type vibration viscometer SV-10 (made by A & D Co., Ltd.).

<Base surface forming resin>
Low density polyethylene (LDPE)
Density: 0.922 g / cm ³
Crystallinity: 0.37

<Liquid diffusion prevention layer forming resin>
Ethylene / vinyl alcohol copolymer (EVOH)
Density: 1.20 g / cm ³
Tg: 60 ° C

<Adhesive layer forming resin>
Maleic anhydride modified polyethylene

<Base material>
Low density polyethylene (LDPE)
Density: 0.922 g / cm ³
Crystallinity: 0.37

<Roughening additive>
Hydrophobic silica Crosslinked polymethyl methacrylate A (Crosslinked PMMA-A)
Average particle size: 3 μm
Cross-linked polymethyl methacrylate B (cross-linked PMMA-B)
Average particle size: 20 μm
Ultra high molecular weight polyethylene (ultra high molecular weight PE)
Average particle size: 10 μm

<Measurement of crystallinity of resin>
Among the resins used, for low density polyethylene, a differential scanning calorimeter (Diamond DSC manufactured by PERKIN ELMER) was used for measurement under the following conditions to determine the crystallinity of the resin.
A sample of about 7 mg of resin is scanned from 25 ° C. to 200 ° C. at a heating rate of 10 ° C./min, held at 200 ° C. for 3 minutes, and scanned from 200 ° C. to −50 ° C. at a cooling rate of 10 ° C./min. And held at −50 ° C. for 3 minutes. Thereafter, the heat of fusion (ΔH) of the resin was determined from the profile obtained when scanning from −50 ° C. to 200 ° C. at a heating rate of 10 ° C./min. The heat of fusion (ΔH) obtained by the measurement was divided by the heat of fusion of complete crystals (ΔH ⁰ ) = 293 J / g for low density polyethylene, and the degree of crystallinity of each was calculated.

<Example 1>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 95 parts by weight Roughening additive 1 part by weight
Nippon Aerosil Co., Ltd. R972
(Dimethylsilyl group-coated hydrophobic silica)
Liquid layer forming liquid 4 parts by weight
Medium chain fatty acid triglyceride (MCT)
The resin composition for forming the base layer described above in a 40 mm extruder, the resin for forming an adhesive layer (maleic anhydride-modified polyethylene) in 30 mm extruder A, and the resin for forming a liquid diffusion preventing layer (both ethylene and vinyl alcohol) in 30 mm extruder B Polymer) and resin for forming substrate (low density polyethylene) are fed to a 50 mm extruder, respectively, a molten parison is extruded from a multilayer die head having a temperature of 210 ° C., and direct blow molding is performed at a mold temperature of 20 ° C. A container composed of a multilayer structure having an amount of 500 g and a weight of 20 g was produced.
Using the prepared container, measure the coverage of the liquid layer, the coating amount of the liquid layer, the sliding speed of the fluid content, the depth and thickness of the liquid diffusion prevention layer, and the total thickness, and observe the surface of the inner surface of the container It was.
FIG. 5 shows a three-dimensional image of the obtained surface shape and a shape profile in an arbitrary cross section.
From the result of measuring the coverage of the liquid layer at the stage of one day after molding, it was confirmed that a liquid layer was formed on the surface of the molded multilayer structure.
Further, the molded container was stored at 22 ° C. and 60% RH for a predetermined period, and the coverage of the liquid layer and the sliding speed of the fluid content were measured. The results are summarized in Table 1.

The layer structure of this container which is a multilayer structure is as follows with the liquid layer as the inner surface.
Liquid layer / Underlayer (35) / Adhesive layer (10) / Liquid diffusion prevention layer (20) / Adhesive layer (10)
/ Base material (340),
Depth of liquid diffusion prevention layer (45)
Overall thickness (415)
Here, the value in parentheses indicates the thickness (μm) of each layer (the same applies hereinafter).

<Example 2>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 94.7 parts by weight Roughening additive 0.3 parts by weight
Cross-linked PMMA-A
Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (80) / Adhesive layer (10) / Liquid diffusion prevention layer (25) / Adhesive layer (10)
/ Base material (370)
Depth of liquid diffusion prevention layer (90)
Overall thickness (495)

<Example 3>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 94 parts by weight Roughening additive 1 part by weight
Cross-linked PMMA-B
Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (80) / Adhesive layer (10) / Liquid diffusion prevention layer (20) / Adhesive layer (10)
/ Base material (300)
Depth of liquid diffusion prevention layer (90)
Overall thickness (420)

<Example 4>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 92 parts by weight Roughening additive 3 parts by weight
Cross-linked PMMA-B
Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (80) / Adhesive layer (10) / Liquid diffusion prevention layer (20) / Adhesive layer (10)
/ Base material (350)
Depth of liquid diffusion prevention layer (90)
Overall thickness (470)

<Example 5>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 94.5 parts by weight Roughening additive 0.5 parts by weight
Ultra high molecular weight PE
Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (80) / Adhesive layer (15) / Liquid diffusion prevention layer (25) / Adhesive layer (10)
/ Base material (340)
Depth of liquid diffusion prevention layer (95)
Overall thickness (470)

<Example 6>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 94 parts by weight Roughening additive 1 part by weight
Ultra high molecular weight PE
Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (85) / Adhesive layer (10) / Liquid diffusion prevention layer (25) / Adhesive layer (10)
/ Base material (350)
Depth of liquid diffusion prevention layer (95)
Overall thickness (480)

<Comparative Example 1>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 96 parts by weight Liquid layer forming liquid 4 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1. Further, FIG. 6 shows a three-dimensional image of the surface shape obtained from the surface observation of the inner surface of the container (resin structure) and a shape profile in an arbitrary cross section.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (40) / Adhesive layer (10) / Liquid diffusion prevention layer (20) / Adhesive layer (10)
/ Base material (320)
Depth of liquid diffusion prevention layer (50)
Overall thickness (400)

<Comparative example 2>
The resin composition for base layer formation of the following composition was prepared.
Low-density polyethylene (LDPE) 95 parts by weight Liquid layer forming liquid 5 parts by weight
Medium chain fatty acid triglyceride (MCT)
A container composed of a multilayer structure was produced in the same manner as in Example 1 except that the above resin composition for forming an underlayer was used. Various measurements were performed in the same manner as in Example 1 using the prepared container. The results are summarized in Table 1.
The layer structure of these containers is as follows, with the liquid layer as the inner surface.
Liquid layer / Underlayer (50) / Adhesive layer (10) / Liquid diffusion prevention layer (10) / Adhesive layer (10)
/ Base material (335)
Depth of liquid diffusion prevention layer (60)
Overall thickness (415)

From the results of the surface shape measurement shown in Table 1 and FIGS. 5 and 6, in Examples 1 to 6, fine protrusions having a height of 0.7 μm or more exist in a density range of 20 to 100 / mm ² , And it turns out that the average protrusion space | interval L exists in the range of 100-300 micrometers. Moreover, it can confirm that those surfaces are coat | covered by the ratio of 0.80 or more with the liquid layer from the result of the liquid layer coverage. On the other hand, in Comparative Examples 1 and 2, it can be confirmed that the projection density of fine projections having a height of 0.7 μm or more is less than 20 / mm ² and the liquid layer coverage is 0.80 or more.
Looking at the sliding properties on these surfaces, there are fine projections having a height of 0.7 μm or more in a density range of 20 to 100 pieces / mm ² , and the average projection interval L is in the range of 100 to 300 μm. In Examples 1 to 6 in which a liquid film was formed on the surface of the fine protrusions , the sliding speed of 12 mm / min or more was exhibited after 5th day in any example (maximum of 18.5 mm / min). In Comparative Examples 1 and 2 in which a liquid film was formed on the surface where the projection density of fine projections having a height of 0.7 μm or more was less than 20 pieces / mm ² , the sliding speed was 8.5 mm / min at the maximum. It can be understood that the sliding speed is improved in Examples 1 to 6.

  From the above results, in the present invention, since the protruding portion (liquid protruding portion) is locally formed on the surface of the liquid layer, the contact area with the fluid content is reduced, and the frictional force with the content is reduced. Therefore, it is considered that excellent slipperiness was expressed.

1: Resin molded body 3: Liquid layer 3a: Liquid convex part 5: Fluid 10: Resin structure 20: Liquid diffusion prevention layer 23: Base material 25: Liquid diffusion control layer 30: Multilayer structure

Claims (5)

In a structure comprising a molded body having a liquid layer on the surface, and a fluid is present on the liquid layer,
The surface supporting the liquid layer is formed with a locally protruding portion, and a portion protruding locally on the surface of the liquid layer corresponding to the protruding portion. Formed,
On the surface of the liquid layer, fine protrusions having a height of 0.7 μm or more are distributed at a density of 20 to 100 pieces / mm ^{2 and} are observed at an average interval of 100 to 300 μm. Structure. The structure according to claim 1, wherein the liquid layer is present on the surface of the molded body in an amount of 0.5 to 30 g / m ² . The structure according to claim 1 or 2 , wherein a surface supporting the liquid layer is made of a resin. The structure according to claim 3, wherein the resin forming the surface supporting the liquid layer is an olefin resin or a polyester resin. The structure according to any one of claims 1 to 4, wherein the molded body has a form of a container.