JP2017144674A - Laminated structure including a wax layer having uneven surface, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated structure including a wax layer having an uneven surface formed with using hydrophobic particles and wax, without using organic solvent.MEANS FOR SOLVING THE PROBLEM: A laminated structure includes a molded body having a surface resin layer 1, and a wax layer 5 having an uneven surface disposed on the surface resin layer 1 of the molded body. The surface resin layer 1 of the molded body is made of a resin having an SP value different from that of the wax 3 by 1.5(MPa)or less, and the wax 3 is absorbed in the resin layer 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated structure including a wax layer having an uneven surface, and further relates to a manufacturing method thereof.

  Plastics are easy to mold and can be easily molded into various forms, and thus are widely used for various applications. For example, various viscous beverages, cooking oils, seasonings, or yogurt It is suitably used as a container for storing various foods, and liquid detergents and pastes.

  By the way, in a container in which viscous liquid contents or gel-like contents are stored, it is possible to effectively prevent the contents from adhering to the inner surface of the container (non-adhesiveness of the contents), or In many cases, it is required to quickly discharge from the container (sliding properties of the contents).

Means for enhancing non-adhesion and sliding properties (hereinafter, these properties may be referred to as slipperiness) to the contents include distributing hydrophobic fine particles on the surface in contact with the contents, Means such as coating with a wax solid content is known (for example, see Patent Documents 1 to 3).
That is, these known means are to impart excellent slipperiness to the contents containing moisture by allowing hydrophobic fine particles and wax to be present on the surface in contact with the contents. is there. In particular, when the hydrophobic fine particles are distributed on the surface, irregularities are formed on the surface, thereby greatly improving the slipperiness with respect to the contents. That is, when the contents move on the uneven surface, the contents move while in contact with the air existing between the unevenness, but the air has the highest water repellency. Accordingly, the water repellency exhibited by the hydrophobic fine particles and the water repellency due to the unevenness are combined to greatly increase the slipperiness with respect to the contents.

JP2012-228787A Patent No. 5490574 Patent No. 4348401

However, all of the conventionally known means using hydrophobic fine particles and wax use a coating solution in which these components are dissolved in an organic solvent, and this coating solution is applied to the surface and dried. Therefore, there has been a problem that the burden on the environment is large for removing the solvent.
Further, even in a structure in which a wax layer formed by the above method is formed on the surface, further improvement in slipperiness is required for the above-mentioned viscous substance.

Accordingly, an object of the present invention is to provide a laminated structure in which a wax layer having a concavo-convex surface formed using hydrophobic fine particles and wax, but without using any organic solvent, and a method for producing the same. There is to do.
Another object of the present invention is to provide a laminated structure having a wax layer having a concavo-convex surface on the surface and having improved slipperiness with respect to a viscous fluid substance and a method for producing the same.

According to the present invention, a molded body having a surface formed of a resin layer and a wax layer having an uneven surface provided on the resin layer on the surface of the molded body, the resin layer on the surface of the molded body is The laminated structure is formed of a resin having a difference in SP value from the wax of 1.5 (MPa) ^1/2 or less, and the wax is absorbed in the resin layer. Is provided.

In the laminated structure of the present invention,
(1) Fine particles that are roughening materials are distributed in the wax layer,
(2) The fine particles have an average primary particle size of 4 nm to 1 μm,
(3) The wax layer has a metaball solid shape connected in a metaball shape in which the fine particles are distributed;
(4) The melting point of the wax is in the range of 40 ° C to 110 ° C,
(5) The molded body has a form of a container, and the wax layer is formed on the inner surface on the side in contact with the contents accommodated in the container,
(6) The container is a bottle made of olefin resin,
Or
(7) the container is a paper-based container;
(8) The molded body has a form of a lid material applied to the container mouth portion by heat sealing, and the wax layer is formed on the surface in contact with the contents stored in the container. Being
Is preferred.

Moreover, according to the present invention,
A step of preparing a wax melt in which fine particles are dispersed and a molded body in which a surface layer is formed of a resin having a difference in SP value between the wax of 1.5 (MPa) ^1/2 or less,
Applying the wax melt to the surface of the molded body;
A step of heating and holding the wax applied to the surface of the molded body in a molten state so that the resin forming the surface layer of the molded body absorbs the wax;
Next, a step of forming a wax layer on the surface layer by cooling and solidifying the wax present on the surface layer,
A method of manufacturing a laminated structure having a wax layer on a surface is provided.

In the above manufacturing method,
When the melting point of the resin forming the surface layer of the molded body is X ° C., heating and holding for maintaining the wax in a molten state is represented by the following conditional expression:
X-5 ≧ Y ≧ X-50
Forming a wax layer having an uneven surface at a temperature Y satisfying
Is preferred.

In the laminated structure of the present invention, a wax layer having an uneven surface is formed on the resin forming the surface layer of the molded body, and the hydrophobicity of the wax itself and the hydrophobic property of the uneven surface are reduced. In combination, the slipperiness with respect to the moisture-containing substance is exhibited. In the present invention, the resin forming the surface layer of the molded body has a difference in SP value from the wax of 1.5. (MPa) It is an important feature that a resin of ^1/2 or less is selectively used.
That is, in the present invention, the SP value is an index called a solubility parameter -δ calculated by the calculation method proposed by Small, and the molar traction force constant for the atoms or atomic groups constituting the molecule and their bond types. The value calculated from the molecular volume (PAJ Small: J. Appl Chem., 3, 71 (1953)). By the way, such SP value is widely used as a scale for evaluating the compatibility between substances. The smaller this difference is, the higher the affinity between both substances is, and the higher the compatibility is. ing.

In the present invention, as described above, since the surface layer of the molded body is formed of a resin having a small SP value difference from the wax, the melt of the wax is applied to the surface of the molded body without using an organic solvent. By doing so, it is possible to easily absorb the resin in the surface layer of the molded body and form a wax layer on the surface layer.
For example, when the surface layer of the molded body is formed of a resin having a SP value difference from the wax larger than the above range, even if a melt of wax is applied to the surface of the molded body, It is not absorbed and merely a wax layer is formed on the surface of the molded body. Of course, even if the difference in SP value is large, if an organic solvent is used, the surface layer of the molded body can absorb the wax, but in this case, the surface of the molded body is deformed.

  The unevenness on the surface of the wax layer is, for example, depending on the form of the molded body, after forming a wax layer by applying a wax melt to the surface of the molded body and solidifying by cooling, transfer or blasting using a stamper or the like, etching In the present invention in which the surface layer of the molded body is formed of a resin having a small difference in SP value from the wax as described above, the surface of the wax melt is roughened. By blending the fine particles (for example, silica), irregularities can be formed on the surface of the wax layer without post-treatment. That is, a part of the wax melt is absorbed in the resin layer on the surface of the molded body, but the fine particles remain on the surface resin layer of the molded body together with the remaining wax. Thus, it is possible to form irregularities on the surface of the wax layer.

  Further, in the present invention, when the wax layer is formed using the wax melt containing the fine particles as described above, the form of the wax layer is a three-dimensional metaball shape in which the fine particles are distributed inside the metaball. Such a metaball-shaped form has a high degree of unevenness due to the formation of voids inside, and exhibits extremely excellent slipperiness with respect to water-containing substances. Is also a great advantage of the present invention.

  Thus, the specific surface structure of the laminated structure of the present invention can be formed without using an organic solvent, which is used for collecting an organic solvent that evaporates upon heating. The burden is completely eliminated, production efficiency can be significantly increased and costs can be reduced, adverse effects on the environment can be avoided, and it is extremely advantageous for industrial implementation. Furthermore, depending on the form of the wax layer, it is extremely high. Slip is developed.

The schematic sectional drawing which shows the most suitable surface structure of the laminated structure of this invention. The schematic sectional drawing which shows the surface structure of the laminated structure different from this invention. The figure which shows the form of the direct blow bottle which is a suitable form of the laminated structure of this invention. The SEM photograph of the uneven | corrugated surface structure produced in each experiment example. The measurement result of the endothermic peak in Experimental Example 1 is shown. The measurement result of the endothermic peak in Experimental Example 2 is shown. The measurement result of the endothermic peak in Experimental Example 3 is shown.

<Surface structure of structure>
Referring to FIG. 1 showing the most preferable surface structure of the laminated structure of the present invention, the laminated structure shown as a whole has a resin layer 1 (hereinafter sometimes referred to as a base resin layer) as a surface layer. And a wax layer 5 formed by the wax 3 provided on the base resin layer 1. Inside the wax layer 5, fine particles 7 as a roughening material are contained. Distributed. In addition, the wax 3 forming the wax layer 5 is absorbed inside the base resin layer 1.

  As understood from FIG. 1, the wax layer 5 formed of the wax 3 is in a state where spherical metaballs 5 a formed of the wax 3 are connected, and the inside of the metaballs 5 a of the wax 3 is connected. Each have a plurality of fine particles 7 distributed therein. In this embodiment, such a metaball-shaped wax layer 5 forms a concavo-convex surface exhibiting hydrophobicity. Generally, the diameter (equivalent circle diameter) of the metaball 5a in the wax layer 5 is a scanning electron. It is in the range of 20 to 200 nm, particularly 50 to 150 nm as measured with a microscope. Further, since the wax layer 5 is formed by connecting the metaballs 5a of the wax 3, a void 9 exists in the inside. Such a wax layer 5 has an uneven surface with a high degree of unevenness including voids inside, and is formed of the hydrophobic wax 3, and thus exhibits high hydrophobicity, a moisture-containing substance, Extremely high slipperiness for hydrophilic substances.

In the metaball-shaped wax layer 5 as described above, a resin (underlying resin) that forms the underlying resin layer 1 is selected such that the difference in SP value from the wax 3 is 1.5 (MPa) ^1/2 or less. Then, on the base resin layer 1 formed of such a base resin, a melt of wax 3 containing particles 7 (that is, not containing an organic solvent) is applied, and the wax 3 is melted. It is a very specific structure formed by heating so that the state is maintained, allowing a portion of the wax 3 to be absorbed by the underlying resin layer 1 and then cooling.

  That is, when the base resin layer 1 is formed of the resin having the SP value as described above, a melt of the wax 3 containing the fine particles 7 is applied on the base resin layer 1 so that the molten state of the wax 3 is maintained. When heated as described above, since the compatibility between the wax 3 and the base resin is high, the wax 3 in the melt is absorbed into the base resin layer 1. At this time, the wax 3 at a position away from the fine particles 7 dispersed in the melt of the wax 3 is preferentially absorbed and diffused by the base resin layer 1 and is present in the vicinity of the fine particles 7. The wax 3 remains on the base resin layer 1 without being absorbed by the base resin layer 1. In this state, the molten wax 3 remaining on the base resin layer 1 is cooled and solidified to form the metaball-shaped wax layer 5 including the voids 9 inside as described above, and the base resin layer The wax 3 is absorbed inside 1. The shape of the metaball as described above is similar to, for example, a space-filling model that is widely used in spatially indicating the chemical structure of a substance, and is shown in the examples described later. Thus, it can confirm with an atomic force microscope and a scanning electron microscope.

Further, as understood from the above description, when the base resin layer 1 is formed of a resin having a SP value difference from the wax 3 larger than the above range, the fine resin 7 is included as described above. Even if the melt of the wax 3 is applied to the base resin layer 1 and heated and held, even if the wax 3 is not absorbed or absorbed by the base resin 1, the amount is very small. As shown in the figure, a flat wax layer 5 is formed, and fine particles 7 are only distributed therein, and an uneven surface due to the wax 3 is not formed. It is unsatisfactory because it is not formed.
Furthermore, even if the base resin layer 1 is formed of a resin having an SP value in the above range, when the coating solution of the wax 3 formed of an organic solvent is applied to the base resin layer 1, the wax 3 is immediately As a result, almost no wax 3 remains on the surface of the base resin layer 1 and only the fine particles 7 are distributed. In some cases, the base resin layer 1 may be deformed by dissolution, and the shape of the molded body having the base resin layer 1 may be impaired.

Base resin layer 1;
As described above, it is necessary to use the base resin layer 1 forming the molding surface having a difference in SP value from the wax 3 of 1.5 (MPa) ^1/2 or less. . That is, in the case where the resin having a large difference in SP value forms the base resin layer 1, the wax 3 is not absorbed by the base resin layer 1, so that the wax layer 5 having the form shown in FIG. Can not. Incidentally, SP values of paraffin wax and typical thermoplastic resins are as follows.
SP value (MPa) ^1/2 Difference in SP value Paraffin wax 17.3 0
Polyethylene (LDPE) 17.9 0.6
Polyethylene (HDPE) 18.7 1.4
Homopolypropylene (h-PP) 16.4 0.9
Cyclic olefin copolymer (COC) 13.8 3.5
Ethylene vinyl call copolymer (EVOH) 18.9 1.6
Polyethylene terephthalate (PET) 22.7 5.4
PET-G 20.4 3.1
PET-G is amorphous polyethylene terephthalate, which is a copolymer polyethylene terephthalate containing a copolymer component.

  Therefore, when paraffin wax is used as the wax 3, polyethylene and polypropylene can be used as the resin for forming the base resin layer 1 on the surface of the molded body.

In the present invention, the resin having a difference in SP value with respect to the wax 3 in the above range varies depending on the type of the wax 3 used, but the SP value of the wax 3 is substantially the same as that of the paraffin wax. Generally, low density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or ethylene, propylene, 1-butene, 4-methyl-1-pentene, (meth) acrylic acid, (meth ) Random or block copolymers of α-olefins such as acrylic ester and vinyl acetate, cyclic olefin copolymers and the like can be exemplified.
In addition, various resins can be blended and used as long as the difference in SP value of the resins forming the matrix falls within the above range.

  In addition, the resin forming the base resin layer 1 may have at least a molecular weight capable of forming a film as long as the difference in SP value is within the above range. In consideration, those having a melt flow rate (MFR) suitable for molding are preferably applied. For example, if the base resin layer 1 is formed by extrusion, one having an MFR suitable for extrusion is preferably used.

  The thickness of the base resin layer 1 as described above is not particularly limited, but in general, it preferably has a thickness of about 5 to 200 μm, particularly about 10 to 100 μm. If this thickness is too thin, the amount of wax 3 absorbed will be reduced, and as a result, the metaball-shaped wax layer 5 will be difficult to be formed, and the hydrophobic effect due to surface irregularities may be reduced. . If the thickness of the base resin layer 1 is larger than necessary, almost all of the wax 3 used is likely to be absorbed by the base resin layer 1, and in this case as well, the metaball shape as shown in FIG. It becomes difficult to form a wax structure.

Wax 3;
The wax 3 used in the present invention has characteristics that it is hydrophobic and solid at room temperature, and can form a stable layer that does not easily fall off on the surface of the base resin layer 1. And has the advantage that it can continuously exhibit a stable slipperiness.
For example, in the case of paraffin wax, it is a white solid at normal temperature produced from a petroleum refining process, and is mainly composed of linear paraffin having about 20 to 30 carbon atoms and containing a small amount of isoparaffin.
When carnauba wax is given as an example of the plant-based wax, it is a light yellow to light brown solid collected from carnabay palm, and mainly contains a hydroxy acid ester having 16 to 34 carbon atoms.

In the present invention, among these waxes 3, those having a melting point in the range of 50 to 100 ° C. are particularly suitable. That is, if the melting point of the wax 3 is too low, the wax 3 flows during use of the structure 10 in summer and the like, and the wax layer 5 in FIG. If the melting point of the wax 3 is too high, the heating temperature for absorbing the wax 3 into the resin layer 1 must be increased, and the operation is limited to extrusion molding, or the resin layer of the wax 3 It may be difficult to effectively absorb 1.
In the present invention, synthetic hydrocarbon waxes, plant waxes, animal waxes, mineral waxes and the like can also be suitably used on the condition that the melting point is within the above range.

  In the present invention, for example, when paraffin wax, polyethylene wax, or microcrystalline wax is used as the wax 3, low-density polyethylene, high-density polyethylene or Polypropylene is preferably used.

  In the present invention, the fact that the wax 3 is absorbed in the base resin layer 1 means that, in the DSC temperature rise curve for the resin layer 1, an endothermic peak derived from the melting point is formed in the low temperature region or due to the solvent. It can be confirmed by extraction.

Fine particles 7;
The fine particles 7 in FIG. 1 are used as a roughening material, and are an essential material for forming the metaball-shaped wax layer 5. That is, if the base resin layer 1 only absorbs the wax 3 and forms the wax layer 5 on the base resin layer 1, such a fine particle 7 is not blended, and the melt of the wax 3 is mixed with the base resin. It only needs to be applied to layer 1. However, in this case, since the wax layer 3 does not have a metaball shape, the surface of the wax layer 5 does not become an uneven surface. Therefore, it is necessary to form an uneven surface by post-treatment such as blasting or etching. Although it is possible to ensure slipperiness by such means, in this case, a special apparatus for post-processing is required, and the wax layer 5 is formed without using an organic solvent. As a result, the advantage of the present invention that the cost can be reduced is diminished. In addition, there is a restriction that the molded body provided with the base resin layer 1 must have a form suitable for post-processing. For example, when the molded body has a form like a bottle, Processing becomes difficult. Furthermore, even if the wax layer 5 having an uneven surface can be formed, a metaball shape having voids 9 therein is not formed, so that the slipperiness is also inferior to the wax layer 5 in the form of FIG. It becomes a thing.
Therefore, in the present invention, it is most preferable to use the fine particles 7 as a roughening material to form a metaball-shaped wax layer 5 as shown in FIG.

  The fine particles 7 used as the roughening material are blended into the melt of the wax 3 and when the melt is applied to the base resin layer 1, the base resin layer is maintained in a granular shape. In general, particles that remain on the base resin layer 1 without being absorbed by the particles 1 are generally used. Particles of inorganic oxides such as silica, titanium oxide, and alumina, and particles of carbonates such as calcium carbonate are generally used. Are preferably used.

In order to form the metaball-shaped wax layer 5 in which the diameter (equivalent circle diameter) of the metaball 5a is in the above-described range (20 to 200 nm, particularly 50 to 150 nm), among the fine particles 7 as described above, The primary particle size (or minimum constitutional unit) is desirably in the range of 3 nm to 1 μm, preferably 5 nm to 500 nm, more preferably 10 nm to 200 nm. In the present invention, the fine particles 7 are presumed to act as a core of the metaball 5a forming the metaball-shaped wax layer 5, and the size of the metaballs is considered to depend on the primary particle diameter of the fine particles 7 to be used. Because it is. Therefore, in the present invention, in order to form the metaball-shaped wax layer 5 exhibiting excellent slipperiness with respect to the content containing moisture, it is preferable to use fine particles 7 having an average primary particle diameter in the above range. .
The average primary particle diameter of the fine particles 7 can be measured by observation with a scanning electron microscope.

The surface of the fine particles 7 as described above is a functional group having a critical surface tension of 30 mN / m or less, for example, an alkyl group such as a methyl group, an alkylsilyl group such as a methylsilyl group, a fluoroalkyl group, or a fluoroalkylsilyl group. It is preferably modified to be hydrophobized. By introducing such a hydrophobic functional group, for example, when the fine particles 7 are dispersed in the wax 3 in a molten state, good dispersion is obtained, and the wax 3 is retained in the vicinity of the fine particles 7, and the The wax layer 5 having a shape can be easily formed, and the wax layer 5 having no partial defects can be formed uniformly.
For example, in the present invention, when 20 μL of pure water is dropped on the surface of the wax layer 5 formed by the connection of the metaballs 5 a including the hydrophobic fine particles 7, the angle of the surface where the pure water slides down is as follows. The defined falling angle can be 5 ° or less, and the slipperiness with respect to the viscous content containing moisture can be remarkably enhanced.

  Such modifications with hydrophobic functional groups include coupling using a hydrophobizing agent having these functional groups (for example, silane compounds, siloxane compounds, silazane compounds, titanium alkoxide compounds, etc.), fatty acids, metal soaps, etc. This is done by the coating used.

  In the present invention, the hydrophobic fine particles 7 that are particularly preferably used are hydrophobic silica fine particles and calcium carbonate fine particles due to cost and availability, and are surface modified with dimethylsilyl groups or trimethylsilyl groups, or with silicone oil. Hydrophobic silica fine particles coated on the surface or calcium carbonate fine particles coated on the surface with a fatty acid or a metal soap are most preferable.

The fine particles 7 described above are distributed in the metaballs 5a forming the wax layer 5 as shown in FIG. 1, but such a surface structure can be easily formed. The amount of surface distribution is slightly different depending on the primary particle size, but generally 30 to 900 mg / m ² , particularly 300 to 600 mg / m ² . It is preferable to be in the range.

Form of the molded body;
In the laminated structure 10 of the present invention, a molded body having the base resin layer 1 on the surface is used, the base resin layer 1 wax 3 of the molded body is absorbed, and the wax layer 5 is formed on the base resin layer 1. Although it has the formed surface structure, as long as it has such a surface structure, the molded body provided with the base resin layer 1 can take various forms.

  For example, the molded body may have a single-layer structure composed only of the resin layer 1 in which the wax 3 is absorbed, or the base resin layer 1 is formed on the surface of glass, metal foil, paper, or the like. It is also possible to have a structure. In particular, when the laminated structure 10 of the present invention is used as a container lid, the base resin layer 1 is often laminated on paper or metal foil.

Furthermore, in this invention, it is also possible to set it as the multilayered structure which laminated | stacked the base resin layer 1 with the other resin layer.
As such a multilayer structure, a structure in which a layer made of a resin having an SP value outside the above-described range is provided below the base resin layer 1 is particularly preferable. That is, the resin having such SP value has a function of suppressing the absorption and diffusion of the wax 3. As a result, the absorption of the wax 3 is stopped by the base resin layer 1, and the above-described metaball-shaped wax 5 This is because it is extremely advantageous for formation.
For example, a layer structure in which an oxygen barrier layer, an oxygen absorbing layer, or a polyester resin layer such as polyethylene terephthalate is appropriately laminated on the lower side of the base resin layer 1 through an adhesive resin layer, Any of the resins used in these layers has a difference in SP value from the wax 3 outside the above-described range, and further absorbs and diffuses the wax 3 from the base resin layer 1. Of course, it is possible to adopt a structure in which a layer that suppresses absorption and diffusion of the wax 3 is sandwiched between the base resin layer 1 and the same kind of resin as the base resin layer 1 is laminated.
Such a multilayer structure of the molded body is applied particularly when the laminated structure 10 is used in the form of a container.

The oxygen barrier layer in the multilayer structure is formed of an oxygen barrier resin such as an ethylene-vinyl alcohol copolymer or polyamide, and the oxygen barrier layer is not limited as long as the oxygen barrier property is not impaired. The thermoplastic resin may be blended with other thermoplastic resins.
The oxygen absorbing layer is a layer containing an oxidizing polymer and a transition metal catalyst, as described in JP-A No. 2002-240813, and the oxidizing polymer is oxygenated by the action of the transition metal catalyst. As a result, the oxygen is absorbed and the permeation of oxygen is blocked. Such an oxidizable polymer and a transition metal catalyst are described in detail in the above-mentioned JP-A-2002-240813 and the like. Olefin resins having tertiary carbon atoms (eg, polypropylene, polybutene-1, etc., or copolymers thereof), thermoplastic polyesters or aliphatic polyamides; xylylene group-containing polyamide resins; ethylenically unsaturated group-containing polymers ( For example, a polymer derived from a polyene such as butadiene). Moreover, as a transition metal type catalyst, the inorganic salt, organic acid salt, or complex salt of transition metals, such as iron, cobalt, and nickel, are typical.
Further, the adhesive resin used for adhesion of each layer is known per se, for example, olefin graft-modified with carboxylic acids such as maleic acid, itaconic acid, fumaric acid or anhydrides thereof, amides, esters, etc. Resin; ethylene-acrylic acid copolymer; ion-crosslinked olefin copolymer; ethylene-vinyl acetate copolymer;
The thickness of each layer described above may be set to an appropriate thickness according to the characteristics required for each layer.
Furthermore, it is also possible to provide as an inner layer a ligide layer obtained by blending scraps such as burrs generated when molding the multilayer structure 10 as described above with a virgin resin such as an olefin resin.

Production of laminated structure 10;
In the laminated structure 10 of the present invention described above, the wax 3 melted with the fine particles 7 is applied to the base resin layer 1 on the surface of the molded body, and the molten state of the wax 3 is thus described. It is preferably manufactured by heating and holding and allowing the base resin layer 1 to absorb the wax and then cooling and solidifying the wax 3.
The amount of the fine particles 7 blended in the melt of the wax 3 is usually 3.0 to 10.0 parts by mass per 100 parts by mass of the wax so that the fine particles can be distributed on the base resin layer 1 in the amount described above. In particular, it is set to about 5.0 to 8.0 parts by mass.
As the melt application means, known methods such as spraying, roller coating, knife coating and the like can be adopted depending on the form of the molded body. For example, when the molded body has a form like a bottle and the base resin layer 1 is formed on the inner surface thereof, spraying is suitably employed.

In the above method, the heating for maintaining the molten state of the wax 3 in the melt of the wax 3 is a treatment necessary for absorbing the wax 3 in the base resin layer 1, and the heating temperature is the wax 3. It is essential that the melting point of the base resin layer 1 is not lower than the glass transition temperature (Tg) of the base resin layer 1 and lower than the melting point of the base resin. In order to carry out the process, when the melting point of the base resin is X ° C., the heating temperature Y is expressed by the following conditional expression:
X-5 ≧ Y ≧ X-50
It is more preferable to set so as to satisfy the above, and it is more preferable to heat and hold the wax melt at such a temperature for 5 seconds to 10 minutes. That is, if the heating temperature Y ° C. is too low with respect to the melting point X ° C. of the base resin, many crystals remain in the base resin layer 1, and the remaining crystals absorb the wax 3 into the base resin layer 1. Is hindered, and it takes a long time to form the wax layer 5 in the form shown in FIG. 1, which tends to be disadvantageous in terms of productivity. If the heating temperature Y ° C. is close to the melting point X ° C. of the base resin, the absorption speed of the wax 3 is too high and most of the wax 3 in the melt is absorbed into the base resin layer 1 in a short time. As a result, there is a tendency that it is difficult to secure the amount of the wax 3 on the base resin layer 1 necessary for forming the wax layer 5 having the form shown in FIG. Incidentally, the crystallinity of the base resin under heating conditions satisfying the above conditions is 60% or less, particularly 5 to 55%. The crystallinity of the base resin under such heating conditions can be calculated from, for example, a crystal melting peak obtained from a DSC temperature rise curve.

  In addition, the said heating for hold | maintaining the molten state of the wax 3 can also be performed once the wax melt apply | coated to the surface is once cooled and solidified.

  Further, the melt of the wax 3 may be applied to the entire surface of the base resin layer 1 forming the surface of the molded body 1, or may be limited to a part of the surface of the base resin layer 1 depending on the application. Then, the melt structure of the wax 3 can be applied to easily form the surface structure as described above. However, the wax layer as shown in FIG. 5 can also be formed in a limited manner.

Form of laminated structure 10;
The laminated structure 10 of the present invention can have various forms depending on the form of the molded body having the base resin layer 1 on the surface, and is particularly slippery (that is, non-adhesive to a viscous substance containing moisture). It is preferable to be used in the form of a packaging material such as a packaging container, a lid material, or a cap.

  In particular, in the cover material, as described above, the base resin layer 1 is often in a form laminated on paper or metal foil, but the aspect in which the surface structure described above is formed on the inner surface of the cover material is as follows. This is advantageous in that adhesion of viscous gel-like or pudding-like products such as yogurt can be prevented. Moreover, in this aspect, since the softening point has fallen because the base resin layer 1 absorbs the wax 3, there is also an advantage that the heat sealability is improved.

  Furthermore, the form of the container to which the present invention is suitably applied is not particularly limited, and forms according to the container material, such as a cup shape, a cup shape, a bottle shape, a bag shape (pouch), a syringe shape, an acupoint shape, and a tray shape. It may have and may be stretch-molded. Other than the container form, there are dishes such as spoons, forks, and lotus roots, kitchen utensils, and lids.

  In such a container, a preformed article having the above-described base resin layer 1 is molded by a method known per se, and this is applied to a film by heat sealing, vacuum molding such as plug assist molding, blow molding or the like. It is post-processed to form a container.

  FIG. 3 shows a direct blow bottle which is the most preferable form of the laminated structure 10 of the present invention. That is, in this bottle-shaped laminated structure generally indicated by 10 in FIG. 3, the molded body provided with the base resin layer 1 is connected to the neck 11 via the neck 11 and the shoulder 13 provided with screws. The body wall 15 and the bottom wall 17 that closes the lower end of the body wall 15 are provided, and the inner surface of such a molded body is formed by the base resin layer 1. By the means described above, the wax 3 is absorbed in the base resin layer 1 on the inner surface of such a bottle-shaped molded body, and the wax layer 5 is formed on the base resin layer 1.

  Since such a structure 10 has a high slipperiness with respect to a moisture-containing viscous substance, in particular, a viscous content (25 ° C.) of 100 mPa · s or more, for example, ketchup, aqueous paste, honey, It is most suitable as a filling bottle for viscous contents such as various sauces, mayonnaise, mustard, dressing, jam, chocolate syrup, milky lotion, liquid detergent, shampoo, rinse and the like.

The invention is illustrated in the following examples.
In addition, the resin etc. which were used for the measurement method of various characteristics performed in the following Examples etc., a physical property, etc. and the material of a structure are as follows.

1. Measurement of sliding angle of distilled water A test piece of 20 mm × 50 mm was cut out from a laminated structure prepared by the method described later.
Solid-liquid interface analysis system DropMaster700 under conditions of 23 ° C.-50% RH
(Manufactured by Kyowa Interface Science Co., Ltd.), the test piece was fixed so that the concave / convex surface structure side was on top, 30 mg of distilled water was placed on the test piece, and the test piece was placed at 1 ° / sec. The angle at which distilled water slipped when it was gradually tilted at a speed of, i.e., the sliding angle was measured. It is evaluated that the smaller the sliding angle value, the better the sliding property of the test piece.

2. Morphological observation of uneven surface structure by SEM A test piece of 10 mm × 30 mm was cut out from a laminated structure prepared by the method described later.
The surface of the uneven surface structure is fixed so that the surface is facing upward, and discharge current is 20 mA, treatment time is 40 sec. Using ion sputtering (E-1045 vertical ion sputtering, manufactured by Hitachi High-Technologies). Under these conditions, the surface of the test piece was coated with a thin metal film of Pt.
Then, the form of the uneven surface structure of the test piece was observed under a condition of 50000 magnification using a field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies) to confirm the form of the uneven surface structure.

3. Evaluation of the crystallinity of the base resin layer under each heating condition Cut out a thin piece of about 3 to 5 mg in weight from the material (film described later) used for the base resin, put it in an aluminum crimp cell, and press-fit it for measurement. A sample was created. Regarding the prepared sample, the crystallinity of the base resin under each temperature condition was evaluated from the profile in the temperature rising process of the sample using a differential scanning calorimeter (Diamond DSC, manufactured by PerkinElmer). The temperature raising conditions given to various base resins are shown below.
<LDPE, HDPE, h-PP>
Temperature increase from −50 ° C. to 200 ° C. at 10 ° C./min <COC, EVOH, PET-G>
The temperature was increased from −50 ° C. to 300 ° C. at 10 ° C./min, and the crystallinity of each resin was calculated using the following formula from the results of the endothermic peak obtained by applying the thermal history.
Crystallinity of base resin (%) = (ΔH ₀ / ΔHm °) × 100
Where
ΔH ₀ ... Heat of fusion of the base resin obtained by measurement (J / g)
ΔHm ° ... Heat of fusion of complete crystal of each base resin (J / g)

For the value of ΔHm ° (J / g), the following values were applied with reference to literature values.
LDPE and HDPE: ΔHm ° = 293 J / g
h-PP: ΔHm ° = 207 J / g
PET: ΔHm ° = 140 J / g
Further, as comparative objects, the endothermic peak of each resin and the heat of fusion ΔH _T under the heating temperature conditions in the examples, that is, the heat of fusion of the resin at 60 ° C., 90 ° C., 120 ° C., 150 ° C., 180 ° C. ΔH ₆₀ , ΔH ₉₀ , ΔH ₁₂₀ and ΔH ₁₅₀ were calculated, and the residual crystallinity under each heating temperature condition was calculated from the values.

<Wax>
Paraffin wax (melting point: 50 to 52 ° C., SP value (δ1): 17.3 (MPa) ^1/2 )

<Base resin>
A film having a thickness of about 400 μm was prepared using each material, and used as a test piece.
(However, PET was evaluated using a biaxially stretched film (thickness: 100 μm).)
Low density polyethylene (LDPE)
Melting point: 108 ° C
Crystallinity: 30%
Glass transition point (Tg): -78 ° C
SP value (δ2): 17.9 (MPa) ^1/2
Difference in SP value from paraffin wax: 0.6
High density polyethylene (HDPE)
Melting point: 132 ° C
Crystallinity: 55%
Glass transition point (Tg): -78 ° C
SP value (δ2): 18.7 (MPa) ^1/2
Difference in SP value from paraffin wax: 1.4
Homo polypropylene (h-PP)
Melting point: 164 ° C
Crystallinity: 42%
Glass transition point (Tg): about 5 ° C
SP value (δ2): 16.4 (MPa) ^1/2
Difference in SP value from paraffin wax: 0.9
Cyclic olefin copolymer (COC)
Crystallinity: Amorphous Glass transition point (Tg): 80 ° C
SP value (δ2): 13.8 (MPa) ^1/2
Difference in SP value from paraffin wax: 3.5
Ethylene vinyl alcohol copolymer (EVOH)
Melting point: 190 ° C
Glass transition point (Tg): 60 ° C
SP value (δ2): 18.9 (MPa) ^1/2
Difference in SP value from paraffin wax: 1.6
Polyethylene terephthalate (PET)
Melting point: 265 ° C
Glass transition point (Tg): 80 ° C
SP value (δ2): 22.7 (MPa) ^1/2
Difference in SP value from paraffin wax: 5.4
PET-G
Crystallinity: Amorphous Glass transition point (Tg): 80 ° C
SP value (δ2): 20.4 (MPa) ^1/2
Difference in SP value from paraffin wax: 3.1

<Roughening material fine particles>
Hydrophobic dry silica Average primary particle size 7 nm, BET specific surface area 220 m ² / g

<Experimental example 1>
Paraffin wax (melting point: 50 to 52 ° C.) was supplied as a wax melt to a 50 ml capacity vial and heated and melted at 70 ° C., and the above-mentioned hydrophobic dry silica was added to prepare a wax mixture in which fine particles were dispersed. . In this wax mixture, the mixing ratio of wax to hydrophobic dry silica (wax: silica) is 93: 7 (weight ratio).
A film prepared by using LDPE as a base resin (thickness: about 400 μm) using a bar coater (# 6) heated to about 70 ° C. while melting and stirring this wax mixture while heating at 70 ° C. ) To prepare a laminated structure.
This laminated structure was heated using an oven under three conditions of 60 ° C.-5 min, 90 ° C.-5 min, and 120 ° C.-5 min to melt the wax component contained in the coating layer of the wax mixture. Thereafter, the laminated structure was cooled at room temperature. With respect to the laminated structure samples before and after heating in the oven prepared by this method, the sliding angle of the distilled water was measured. The obtained sliding angle values are summarized in Table 1. Moreover, the form observation of the uneven | corrugated surface structure by SEM was also performed. The obtained observation image is shown in FIG.
In addition, using the film used for the production of the laminated structure, the crystallinity of the base resin layer under each heating condition was evaluated, and the change in the endothermic peak of the sample was measured. The result is shown in FIG.
Furthermore, the amount of heat of fusion ΔH _T of the resin under each heating temperature condition was determined from the results of FIG. 5 and the crystallinity was calculated. The results are shown in Table 2.

<Experimental example 2>
A laminated structure was produced in the same manner as in Experimental Example 1 except that HDPE was used as the material for the base resin film, and the sliding angle of distilled water was measured and the morphology of the uneven surface structure was observed by SEM. The measurement result of the sliding angle is shown in Table 1, and the morphology observation result (SEM photograph) of the uneven surface structure is shown in FIG.
Moreover, the crystallinity of the base resin layer under each heating condition was evaluated using the film used for the production of the laminated structure, and the change in the endothermic peak of the sample was measured. The result is shown in FIG.
Furthermore, the amount of heat of fusion ΔH _T of the resin under each heating temperature condition was determined from the results of FIG. 6 and the crystallinity was calculated. The results are shown in Table 2.

<Experimental example 3>
A laminated structure was produced in the same manner as in Experimental Example 1, except that h-PP was used as the material for the base resin film and 150 ° C.-5 min was added as the heating condition for the laminated structure. And the morphology of the uneven surface structure was observed by SEM. The measurement result of the sliding angle is shown in Table 1, and the morphology observation result (SEM photograph) of the uneven surface structure is shown in FIG.
In addition, using the film used for the production of the laminated structure, the crystallinity of the base resin layer under each heating condition was evaluated, and the change in the endothermic peak of the sample was measured. The result is shown in FIG.
Furthermore, the amount of heat of fusion ΔH _T of the resin under each heating temperature condition was determined from the results of FIG. 7, and the crystallinity was calculated. The results are shown in Table 2.

<Experimental example 4>
Except for using COC as the material for the base resin film, a laminated structure was prepared in the same manner as in Experimental Example 3, and the sliding angle of distilled water was measured and the morphology of the uneven surface structure was observed by SEM. went. The measurement result of the sliding angle is shown in Table 1, and the morphology observation result (SEM photograph) of the uneven surface structure is shown in FIG.

<Experimental example 5>
A laminated structure was produced in the same manner as in Experimental Example 4, except that EVOH was used as the material for the base resin film, except that 60 ° C.-5 min was added as the heating condition of the laminated structure, and 180 ° C.-5 min was added. The sliding angle of distilled water was measured and the morphology of the uneven surface structure was observed by SEM. The measurement result of the sliding angle is shown in Table 1, and the morphology observation result (SEM photograph) of the uneven surface structure is shown in FIG.

<Experimental example 6>
A laminated structure was prepared in the same manner as in Experimental Example 4 except that PET was used as the material for the base resin film, and the sliding angle of distilled water was measured. The results are shown in Table 1.

<Experimental example 7>
A laminated structure was prepared in the same manner as in Experimental Example 4 except that PET-G was used as the material for the underlying resin film, and the sliding angle of distilled water was measured and the morphology of the uneven surface structure was observed by SEM. . The measurement result of the sliding angle is shown in Table 1, and the morphology observation result (SEM photograph) of the uneven surface structure is shown in FIG.

From the results in Table 1, when LDPE was used as the base resin, the sliding angle was 22 ° under the conditions of 60 ° C.-5 min, and good liquid repellency was not obtained. Next, when heated at 90 ° C. for 5 min, the sliding angle was 1 °, and very good liquid repellency was obtained.
However, when the temperature was further raised and the heating was performed under the condition of 120-5 min, the sliding angle greatly increased and the liquid repellency tended to be lost.
Moreover, the result of having observed the surface about these samples using SEM was shown in FIG.
With respect to the sample heated at 60 ° C. for 5 min, the surface condition tended to be smooth. On the other hand, with respect to the sample heated at 90 ° C. for 5 minutes with good liquid repellency, a large number of fine metaball-like structures having a diameter equivalent to a circle of about 100 nm are formed on the surface. confirmed. However, with respect to the sample heated under a temperature condition equal to or higher than the melting point of the LDPE at 120 ° C. for 5 minutes, there was a tendency that the metaball-shaped uneven structure was not formed.
Therefore, good liquid repellency was obtained in the sample in which the metaball-shaped uneven structure was formed, and there was a tendency that good liquid repellency was not obtained in the sample in which the uneven structure was not formed.
Further, as a result of evaluating the crystallinity of the base resin layer under each heating condition, reading from the graph shown in FIG. 5 shows that an endothermic peak begins to appear at about 30 ° C. for LDPE. From this, it is shown that the melting of the crystal part starts and the amorphous part gradually increases as the temperature rises. Thereafter, since the peak reaches a peak at 109 ° C., the melting point is reached at 109 ° C., and it can be evaluated that the crystal part is completely melted and amorphous in a temperature range higher than that.
The endothermic peak of this LDPE and the heating temperatures in this example, 60 ° C., 90 ° C., and 120 ° C., were collated, and the crystallinity ΔH ₆₀ , ΔH ₉₀ , ΔH ₁₂₀ under each temperature condition was determined, and Table 2 It was described in. When this value is compared with the result of surface observation, the surface state does not change when the test piece when heated at 60 ° C., that is, when the crystallinity of the resin is substantially unchanged (ΔH ₆₀ ≈ΔH ₀ ). There was a trend.
In addition, when the test piece when heated at 90 ° C., that is, in a state where the crystal part of the resin is melted to some extent (ΔH ₉₀ <ΔH ₀ ), the surface structure tends to change and a metaball-like structure tends to be formed. It was seen.
Furthermore, when the test piece was heated at 120 ° C., that is, in the state where all of the crystal part of the resin was melted (ΔH ₁₂₀ = 0), there was a tendency that the uneven structure was not formed.

Experimental example 2 shows an example in which HDPE is used as the base resin. From the results in Table 1, when the heating conditions are 60 ° C.-5 min and 90 ° C.-5 min, the sliding angle is 17 °, which is good. Whereas liquid repellency was not obtained, when heated at 120 ° C. for 5 minutes, the sliding angle was 1 °, and a very good liquid repellency tended to be obtained.
The result of having observed the surface about these samples is shown in FIG.
When heated under the conditions of 60 ° C.-5 min and 90 ° C.-5 min, no fine uneven structure is seen on the surface, but for the sample heated under the conditions of 120 ° C.-5 min, the surface has a fine metaball shape. It was confirmed that the structure was formed. However, with respect to the sample heated at a temperature higher than the melting point of HDPE at 150 ° C. for 5 minutes, a result that a metaball-shaped structure was not formed was obtained.
Further, as a result of the evaluation of the crystallinity of the base resin layer under each heating condition, when read from the graph shown in FIG. 6, an endothermic peak begins to appear at about 105 ° C. for HDPE. From this, it is shown that the melting of the crystal part starts and the amorphous part gradually increases as the temperature rises. Thereafter, since the peak reaches the peak at 131 ° C., it can be evaluated that 131 ° C. is the melting point, and in the temperature region higher than that, all the crystal parts are melted and are in an amorphous state.
The endothermic peak of HDPE is compared with the heating temperatures in this example, which are 60 ° C., 90 ° C., 120 ° C., and 150 ° C., and the degree of crystallinity ΔH ₆₀ , ΔH ₉₀ , ΔH ₁₂₀ , ΔH under each temperature condition ₁₅₀ was obtained. The results are shown in Table 2.
Comparing this value with the results of surface observation, when the test piece is heated at 60 ° C., that is, when the crystallinity of the resin is not changed (ΔH ₆₀ ≈ΔH ₀ ), the surface state does not change. It was observed.
In addition, the test piece when heated at 90 ° C. is in a state where the resin crystallinity is not changed (ΔH ₉₀ ≈ΔH ₀ ), and the surface structure does not change, and there is a tendency that the uneven structure is not formed. It was.
On the other hand, when the test piece when heated at 120 ° C., that is, in a state where the resin crystal part is melted to some extent (ΔH ₁₂₀ <ΔH ₀ ), the surface structure tends to change and a metaball-like structure tends to be formed. It was.
However, when the test piece was heated at 150 ° C., that is, in a state where all the crystal parts of the resin were melted (ΔH ₁₅₀ = 0), the uneven structure tended to be not formed.

Experimental Example 3 shows an example in which h-PP is used as the base resin. From the results shown in Table 1, when the heating conditions are 60 ° C.-5 min, 90 ° C.-5 min, and 120 ° C.-5 min, the sliding angle However, when the liquid was heated at 150 ° C. for 5 minutes, the sliding angle was 1 °, and the liquid repellency tended to be improved.
The result of having observed the surface about these samples is shown in FIG.
When heated under conditions of 60 ° C.-5 min, 90 ° C.-5 min, 120 ° C.-5 min, a fine uneven structure is not seen on the surface, but for a sample heated under the conditions of 150 ° C.-5 min, It was confirmed that a fine metaball-shaped structure was formed.
In addition, as a result of evaluating the crystallinity of the base resin layer under each heating condition, as read from the graph shown in FIG. 7, an endothermic peak starts to appear at about 110 ° C. for h-PP. It is shown that the melting of the crystal part starts from 110 ° C., and the amorphous part gradually increases as the temperature rises. Thereafter, since the peak reaches the peak at 164 ° C., 164 ° C. is the melting point, and it can be evaluated that the crystalline portion is completely melted and amorphous in a temperature range higher than that.
This endothermic peak of h-PP is compared with the heating temperatures in this example, which are 60 ° C., 90 ° C., 120 ° C., and 150 ° C., and the crystallinity under each temperature condition ΔH ₆₀ , ΔH ₉₀ , ΔH ₁₂₀ , ΔH ₁₅₀ was determined. The results are summarized in Table 3.
Comparing this value with the results of surface observation, when the test piece is heated at 60 ° C., that is, when the crystallinity of the resin is not changed (ΔH ₆₀ ≈ΔH ₀ ), the surface state does not change. It was observed.
Further, the test piece when heated at 90 ° C. was in a state where the crystallinity of the resin was not changed (ΔH ₉₀ ≈ΔH ₀ ), and a tendency that the surface structure did not change was observed.
Further, the test piece when heated at 120 ° C. was in a state where the crystallinity of the resin was not changed (ΔH ₁₂₀ ≈ΔH ₀ ), and a tendency that the surface structure did not change was observed.
Compared with these, when the test piece is heated at 150 ° C., that is, when all of the crystal part of the resin is melted (ΔH ₁₅₀ <H ₀ ), the surface structure changes and a metaball-like structure is formed. The tendency was seen.

Experimental Example 4 shows an example in which COC is used as the base resin. From the results in Table 1, when the heating conditions are 60 ° C.-5 min and 90 ° C.-5 min, the sliding angle is 31 °. However, when the liquid was heated at 120 ° C. for 5 minutes and 150 ° C. for 5 minutes, the sliding angle was 8 ° and 10 °, and the liquid repellency was improved. There was a trend.
However, there was no heating condition for the sliding angle to be 1 °, and the results showed different behavior from LDPE, HDPE, and h-PP.
The result of having observed the surface about these samples is shown in FIG. Samples heated under conditions of 60 ° C.-5 min and 90 ° C.-5 min have a smooth surface, whereas samples heated under conditions of 120 ° C.-5 min and 150 ° C.-5 min are derived from fine particles. Then, it was seen that a concavo-convex structure having a particle size of about 50 nm to 200 nm was formed. However, even when the concavo-convex structure was formed, there was a tendency that it was not uniformly formed on the entire surface.

Experimental Example 5 shows an example in which EVOH is used as the base resin, but as shown in Table 1, the super-water-repellent state with a sliding angle of 1 ° is obtained when heated under any heating condition. The result which was not obtained was seen.
Moreover, the result of having observed the surface regarding the sample after heating on each temperature condition is shown in FIG. As can be seen from this result, when EVOH is used as the base resin, it can be confirmed that the surface shape does not change and is smooth even when heated under any conditions.

  Experimental Example 6 shows an example in which PET is used as the base resin. However, as shown in Table 1, even when heated under any heating condition, a super-water-repellent state with a sliding angle of 1 ° is shown. The result which was not obtained was seen.

In Experimental Example 7, an example in which PET-G is used as the base resin is shown. However, as shown in Table 1, even when heated under any heating condition, the super water repellent with a sliding angle of 1 ° is shown. The result was not obtained.
Moreover, the result of having observed the surface regarding the sample after heating on each temperature condition is shown in FIG. As can be seen from this result, when PET-G is used as the base resin, it can be confirmed that the surface shape does not change and is smooth even when heated under any conditions.

Therefore, from these results, as a condition for obtaining good liquid repellency,
(1) The SP value of paraffin wax as a dispersion medium is close to the SP value of the base resin.
That is, when δ ₁ -δ ₂ is 2.0 or less,
(2) When the laminated structure after application is heated, the crystal of the base resin is melted to some extent and the crystal part remains (0 <ΔH _T <ΔH ₀ ), that is, As a condition for creating the state of
When heated at a temperature Y satisfying X-5 ≧ Y ≧ X-50 for 5 to 10 minutes,
(3) The case where the base resin is a crystalline resin can be mentioned, and when all of these conditions are satisfied, a tendency of forming a metaball-shaped uneven structure was observed.

With regard to the concavo-convex structure of the metaball shape obtained under these conditions, the concavo-convex structure is a three-dimensionally stacked structure and has a large amount of fine voids. It is considered that a particularly high liquid repellency is expressed.
The reason for the formation of such a structure is that when the laminated structure is heated, the paraffin wax used as a dispersion medium diffuses into the base resin and is absorbed. it is conceivable that. When the compatibility between the paraffin wax and the base resin is low, that is, when the difference between δ1 and δ2 is large, the diffusion itself into the base resin does not occur, or the diffusion speed is very slow, so the wax existing on the outermost surface It is considered that a metaball-shaped structure is not formed because the components are not reduced and the surface is kept smooth.
Further, when heating the laminated structure after coating, under the condition that the crystal part of the base resin is not melted at all (ΔH ₀ ≈ΔH _T ), the crystal part of the base resin suppresses the diffusion of paraffin wax, and the base resin It is thought to have a function to prevent absorption into the layer. As a result, it is considered that the outermost wax component does not decrease, the surface is kept smooth, and a metaball-shaped structure is not formed.

On the other hand, when heated under the melting condition (ΔH = 0) where the base resin is completely melted, that is, the melting point of the base resin or higher, it is considered that the crystal part is completely melted and the paraffin wax is diffused well. At the same time, since the base resin itself melts and becomes liquid, it is considered that the wax structure and the hydrophobic fine particles themselves are drawn into the base resin layer. As a result, it is considered that a metaball-shaped uneven structure is not formed.
When the base resin is an amorphous resin (COC, PET-G), it is presumed that the same phenomenon as that in the state where the crystal part is completely melted is generated, and the uneven structure is not formed.

  Therefore, this technology selects a dispersion medium that is highly compatible with the base resin, coats the surface with fine particles dispersed in the dispersion medium, and the crystal structure of the base resin sufficiently melts the laminated structure. However, it is presumed that a metaball-shaped structure is formed on the surface only when the wax component is absorbed into the base resin by heating under the condition that the crystal part remains.

1: Resin layer on the surface of the molded body (underlying resin layer)
3: Paraffin wax 5: Wax layer 7: Fine particles 10: Laminated structure

Claims (11)

The molded body has a surface formed of a resin layer and a wax layer having an uneven surface provided on the resin layer on the surface of the molded body, and the resin layer on the surface of the molded body has an SP with the wax. A laminated structure characterized by being formed of a resin having a value difference of 1.5 (MPa) ^1/2 or less, and the resin layer absorbing the wax.   The laminated structure according to claim 1, wherein fine particles as a roughening material are distributed in the wax layer.   The multilayer structure according to claim 2, wherein the fine particles have an average primary particle diameter of 4 nm to 1 μm.   The laminated structure according to claim 2, wherein the wax layer has a three-dimensional metaball shape that is continuous in a metaball shape in which the fine particles are distributed.   The laminated structure according to claim 1, wherein the melting point of the wax is in the range of 40C to 110C.   The laminated structure according to claim 1, wherein the molded body has a form of a container, and the wax layer is formed on an inner surface on a side in contact with the contents contained in the container.   The laminated structure according to claim 6, wherein the container is a bottle made of an olefin resin.   The laminated structure according to claim 6, wherein the container is a paper-based container.   The molded body has a form of a lid material applied to a container mouth portion by heat sealing, and the wax layer is formed on a surface on a side in contact with contents stored in the container. 2. The laminated structure according to 1. A step of preparing a wax melt in which fine particles are dispersed and a molded body in which a surface layer is formed of a resin having a difference in SP value between the wax of 1.5 (MPa) ^1/2 or less,
Applying the wax melt to the surface of the molded body;
A step of heating and holding the wax applied to the surface of the molded body in a molten state so that the resin forming the surface layer of the molded body absorbs the wax;
Next, a step of forming a wax layer on the surface layer by cooling and solidifying the wax present on the surface layer,
A method for producing a laminated structure comprising a wax layer on a surface, characterized by comprising: When the melting point of the resin forming the surface layer of the molded body is X ° C., heating and holding for maintaining the wax in a molten state is represented by the following conditional expression:
X-5 ≧ Y ≧ X-50
The method according to claim 10, wherein a wax layer having an uneven surface is formed at a temperature Y satisfying the conditions of 5 seconds to 10 minutes.