JP2016101730A - Bird dropping easy removal member and method for removing bird dropping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bird dropping easy removal member capable of easily removing most of bird dripping adhering to a surface only by flowing water to the surface; and to provide a method for removing the bird dropping.SOLUTION: A bird dropping easy removal member has a synthetic resin substrate 1 and a bird dropping easy removal member having a bird dropping easy removal layer 2 formed on the synthetic resin substrate 1. A value of a polarity term γof surface free energy γof the bird dropping easy removal layer 2 is 5.0 mJ/mor less. A ratio of the polarity term to the surface free energy γis 8.0% or less. A method for removing the bird dropping flows the surface of a bird dropping easy removal layer of the bird dropping easy removal member with water, and removes most of the bird dripping adhering to a surface of the bird dropping easy removal layer. When a value of the polarity term γis 5.0 mJ/mor less and a ratio of the polarity term to the surface free energy γis 8.0% or less, adhesion of the bird dropping due to electric adsorption of albumin contained in the bird dropping is lowered, and stain resistance (bird dropping stain resistance) against the bird dropping is enhanced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an easy-to-removal member for bird droppings and a method for removing bird droppings, and more specifically, an easy-to-removing member for bird droppings that can easily remove most of the bird droppings attached to the surface simply by flowing water on the surface. The present invention relates to a method for removing the bird droppings.

  Materials for exteriors such as carports and roofing materials are preferably antifouling (contamination resistant), and among them, it is desirable to develop materials that can easily remove bird droppings that are difficult to remove with rainwater. ing.

By the way, as a resin composition having antifouling properties (contamination resistance), for example, at least one kind of resin selected from resins having a critical surface tension of 40 dyne / cm or less, a silicone resin and an antibacterial agent are used. Dispersed ones have already been proposed (Patent Document 1).
This resin composition can exhibit a good water repellency and antifouling effect by lowering the surface free energy by the synergistic action of a resin having a critical surface tension of 40 dyne / cm or less and a silicone resin. .

JP-A-6-287477

  However, even if it is a water-repellent material with low surface free energy, which is said to have high antifouling properties, it is difficult to remove the pseudo bird droppings that are easy to remove if they are tested with water to remove them. There was a thing, and a big difference was seen in the antifouling property to pseudo bird droppings. From this, it was found that in order to obtain a material having good antifouling properties against bird droppings, it is not sufficient to simply reduce the surface free energy of the material.

  The present invention has been made under the circumstances described above, and the object of the present invention is a bird dropping facilitation removal member that can easily remove most of the bird droppings adhering to the surface just by flowing water on the surface, It is in providing the removal method of the bird droppings.

  The present inventors have found that the adhesion of bird droppings is related to the electroadsorption of proteins (eg, albumin) contained in bird droppings, and the electroadsorption of albumin is free from the surface of the solid to which bird droppings adhere. As a result of intensive research on the relationship between the polar term of surface free energy and antifouling property against bird droppings (pseudo bird droppings) And the antifouling property against bird droppings, and if the polar term is below a certain value and the ratio of the polar term to the surface free energy is below a certain value, the antifouling property against the bird droppings The present invention was completed by finding the fact that (fouling resistance to bird droppings) was reliably improved and that most of the attached bird droppings could be easily removed by flushing with water.

That is, the bird dropping easily removal member of the present invention is a bird dropping easy removal member having a synthetic resin base material and a bird dropping easy removal layer formed on the surface thereof, and the surface free energy of the bird dropping easy removal layer is reduced. The value of the polar term is 5.0 mJ / m ² or less, and the ratio of the polar term to the surface free energy is 8.0% or less.
In this specification, the surface free energy value, the polar term value, and the dispersion term value are obtained by measuring the contact angle with respect to the surface of the easy-to-remove layer using two types of liquids, and the extended Fowkes equation (Owens and Wendt method). ) Is obtained by substituting

  In the bird excrement removal member of the present invention, the bird excrement removal layer preferably contains a copolymer of a polycarbonate and a monomer or polymer having Si atoms, and further contains an ultraviolet absorber.

  In addition, the method for removing bird droppings of the present invention is such that water is allowed to flow on the surface of the bird dropping removal layer of the bird dropping removal member, and the bird droppings adhered to the surface of the bird dropping removal layer before flowing the water. It is characterized by removing most of it. Here, “flowing water on the surface of the easy removal layer of bird droppings” not only means that water is gently flowed on the surface of the removal layer of easy removal of bird droppings, It also includes the case where the rain water is run down and the water is flushed.

Proteins contained in bird droppings, such as albumin, are positively and negatively charged everywhere in the molecule, and this is considered to be electrically adsorbed to the adherend to cause the attachment of bird droppings. The polarity term of the surface free energy of the bird dropping easily removal layer is 5.0 mJ / m ² or less as the adherend is the bird dropping removal member of the present invention, and occupies the surface free energy. If the ratio is 8.0% or less, the adherence of bird droppings due to the electroadsorption of albumin is reduced, so that the antifouling property against bird droppings (bird dropping resistance) is improved. As shown in the data, it is possible to easily remove most of the bird droppings by flowing water, and the cleaning rate is greatly improved.

  In particular, if the easy-to-removal layer for bird droppings contains a copolymer of polycarbonate and a monomer or polymer having Si atoms, the removal layer for easy removal of bird droppings containing, for example, a fluororesin having a lower surface free energy value than this. It is possible to obtain a bird dropping easily removing member having a high cleaning rate that is almost the same as that of the member having the environmental impact and reducing the cost as compared with the bird dropping easily removing layer containing a fluorine-based resin. .

  Furthermore, as shown in the data of the examples described later, those containing an ultraviolet absorber in the easy-to-removal layer of bird droppings, the value of the polar term of the surface free energy than those not containing the ultraviolet absorber, and The ratio of the polar term is reduced, so that the antifouling property against bird droppings (bird dropping resistance) is further improved, and the removal of bird droppings becomes easier and the washing rate is improved.

  In addition, the method for removing bird droppings of the present invention is such that water is allowed to flow on the surface of the bird dropping removal layer of the bird dropping removal member, and the bird droppings adhered to the surface of the bird dropping removal layer before flowing the water. Since most of the water is removed, for example, even if rainwater falls on the easy-to-removal layer of bird droppings, most of the attached bird droppings can be removed naturally, and the labor of cleaning can be saved.

It is sectional drawing which shows one Example of the bird dropping facilitation removal member which concerns on this invention.

  The bird dropping faecal removal member shown in FIG. 1 is obtained by forming a bird dropping faecal removal layer 2 on the surface of a synthetic resin base material 1. As the synthetic resin base material 1, a known thermoplastic synthetic resin such as polycarbonate is used. Films, sheets, plates, etc. made of polyester resins, polyvinyl chloride resins, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acrylic resins, and cellulose resins A base material having a shape or a base material having various three-dimensional shapes such as a block shape, a column shape, a tubular shape, and an irregular shape is used. Among these synthetic resin base materials 1, a polycarbonate resin, preferably a polycarbonate resin having a viscosity average molecular weight of 10,000 to 50,000, and having a suitable amount of an ultraviolet absorber in advance to improve weather resistance. You may use the base material which consists of a polycarbonate resin which has this, and the base material which has the heat ray shielding function which contained the pigment, the heat ray absorber, and the heat ray reflective agent in polycarbonate resin. Moreover, the base material which consists of a well-known thermosetting resin is also used. Furthermore, the synthetic resin substrate 1 may contain various additives such as an antioxidant, a pigment, a flame retardant, a heat ray shielding agent, and an antistatic agent.

The synthetic resin base material 1 may be a colored one (for example, a semi-colored milk base material). A light-transmitting synthetic resin base material having a total light transmittance of 80% or more and a haze of 10% or less is selectively used. Also good.
Further, the synthetic resin substrate 1 may be a substrate made of a laminate in which a plurality of different types of synthetic resin layers are laminated.

On the other hand, the bird dropping facilitating removal layer 2 is a synthetic resin for improving the antifouling property (bird dropping resistance) against the bird droppings so that most of the bird droppings can be easily removed simply by flowing water over the surface. According to Fowkes, the surface free energy γ _s of the layer 1 formed on the surface of the substrate 1 is expressed by the dispersion term γ _sd ( The sum of the dispersion component) and the polar term γ _sp (polar component). The values of the dispersion term γ _sd and the polar term γ _sp are obtained from the following [Equation 4] from the extended Fowkes equation (Owens and Wendt method) of the following [Equation 2] and the Young equation of the following [Equation 3]. , Measure the contact angle θ with two types of liquids with known surface free energy component values (γ _ld , γ _lp ), and substitute the contact angles into the following [Equation 4] to obtain simultaneous equations Is obtained by solving Then, the surface free energy γ _s can be obtained by substituting the values of the dispersion term γ _sd and the polarity term γ _sp into the following [Equation 1].
(Equation 1)
γ _s = γ _sd + γ _sp
(Equation 2)
γ _s + γ _L −γ _sL = 2 (γ _sp · γ _Lp ) ^1/2 +2 (γ _sd · γ _Ld ) ^1/2
(Equation 3)
γ _s = γ _SL + γ _L cos θ
(Equation 4)
γ _L (1 + cos θ) / 2γ _Ld = γ _sp ^1/2 (γ _Lp / γ _Ld ) ^1/2 + γ _sd ^1/2
γ _s : surface free energy of solid (bird droppings removal layer) γ _sd : solid dispersion term (dispersion component)
γ _sp : polar term of solid (polar component)
γ _L : surface free energy of liquid γ _sL : free energy at interface between solid and liquid γ _Ld : dispersion term of liquid γ _Lp : polarity term of liquid θ: contact angle

The specific values of the surface free energy γ _s , the dispersion term γ _sd , and the polar term γ _sp of the bird dropping facilitating removal layer 2 are determined by the above method. In the examples of the present invention, as described later, It is obtained by measuring the contact angle of water and hexadecane.

The easy removal layer 2 is a water-repellent layer having a surface free energy γ _s of 60 mJ / m ² or less, preferably 35 mJ / m ² or less, and exhibiting good antifouling properties. In order to reliably improve antifouling property against bird droppings (bird dropping resistance), the surface free energy γ _{s has} a polar term γ _sp of 5.0 mJ / m ² or less and surface free This is a layer formed by selecting the constituent material and composition of the bird dropping facilitating removal layer 2 so that the ratio of the polar term γ _sp to the energy γ _s is 8.0% or less.

［式中、Ｒ１及びＲ２は、それぞれ独立に炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基、Ｘは単結合、炭素数１〜８のアルキレン基、炭素数２〜８のアルキリデン基、炭素数５〜１５のシクロアルキレン基、炭素数５〜１５のシクロアルキリデン基、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−Ｏ−又は−ＣＯ−、ａ及びｂは、それぞれ独立に０〜４の整数を示す。］

[式中、Ｒ３及びＲ４は、それぞれ独立に水素原子、ハロゲン原子又は炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基もしくは炭素数６〜１２のアリール基を示す。］

[式中、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９及びＲ１０は、各々独立に水素原子、炭素数１〜１２のアルキル基又は炭素数６〜１２の置換若しくは無置換のアリール基であり、Ｒ１１及びＲ１２は夫々独立して水素原子、ハロゲン原子、炭素原子数１〜１０のアルキル基、炭素原子数１〜１０のアルコキシ基であり、ｐは自然数であり、ｑは０又は自然数であり、ｐ＋ｑは１００未満の自然数である。Ｘは炭素数２〜８の二価脂肪族基である。]
また、上記フッ素系樹脂としては、例えば、テトラフルオロエチレン・パーフルオロアルキルビニルエーテル共重合体、テトラフルオロエチレン・ヘキサフルオロプロピレン共重合体、テトラフルオロエチレン樹脂、テトラフルオロエチレン・エチレン共重合体、ポリクロロトリフルオロエチレン樹脂等が挙げられる。 Examples of the constituent material of the easy-to-exclude bird dropping layer 2 satisfying the above conditions include a copolymer of a polycarbonate and a monomer or polymer having a Si atom, a fluorine resin, and the like. Specific examples of the monomer or polymer having an Si atom, which is one component of the copolymer, include siloxane (for example, organic monosiloxane and organic polysiloxane).
Specific examples of a copolymer of a polycarbonate and a monomer or polymer having an Si atom include a polycarbonate block composed of a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (II). A polycarbonate-polyorganosiloxane copolymer comprising the following polyorganosiloxane block, and a polycarbonate-polydiorganosiloxane comprising the polycarbonate block represented by the following general formula (I) and the polydiorganosiloxane block represented by the following general formula (III) A copolymer etc. are mentioned.

[Wherein, R 1 and R 2 are each independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, X is a single bond, an alkylene group having 1 to 8 carbon atoms, and 2 to 8 carbon atoms. alkylidene group, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S -, - SO -, - SO 2 -, - O- or -CO-, a and b are each Independently represents an integer of 0-4. ]

[Wherein, R 3 and R 4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. ]

[Wherein R5, R6, R7, R8, R9 and R10 are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R12 is independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, p is a natural number, q is 0 or a natural number, and p + q is It is a natural number less than 100. X is a C2-C8 divalent aliphatic group. ]
Examples of the fluorine resin include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene resin, tetrafluoroethylene / ethylene copolymer, polychloroethylene. A trifluoroethylene resin etc. are mentioned.

  It is not always necessary to form the bird dropping facilitating removal layer 2 using only these constituent materials, and it may be formed by mixing with other resins. For example, when the constituent material is a copolymer of the above polycarbonate and a monomer or polymer having an Si atom, a polycarbonate resin having good compatibility is suitable as the other resin mixed therewith. The mixing ratio of the above copolymer and polycarbonate resin is not particularly limited, but it is appropriate that the weight ratio is 10 to 100: 90 to 0. Even when the proportion of the polycarbonate resin in 100 parts by weight of the constituent resin of the layer 2 increases to 90 parts by weight, as shown in the data of Example 1 described later, the cleaning rate (removal rate) of the pseudo bird droppings is 84%. The high bird dropping facilitating removal layer 2 can be formed. Therefore, the amount of the polycarbonate resin that is less expensive than the above-mentioned copolymer can be increased and the amount of the expensive copolymer can be reduced, so that a cost reduction effect can be obtained.

When the easy-to-removal layer 2 made of the above-described constituent material or the easy-to-removable layer 2 containing the above-described constituent material is formed, the surface free energy γ _s of the surface free energy γ _s is obtained as shown in the data of the examples described later. The value is 35 mJ / m ² or less, the value of the polar term γ _sp is 5.0 mJ / m ² or less, and the ratio of the polar term γ _sp to the surface free energy γ _s is 8.0% or less. Good antifouling property (anti-fouling resistance) can be exhibited sufficiently.

When the easy-to-removal layer 2 is formed with the above-mentioned fluororesin, the desired good resistance to bird droppings can be expressed, but since it contains a halogen substance, it has a disadvantage of high environmental burden and high cost. Occurs. On the other hand, when the bird dropping facilitating removal layer 2 is formed on the surface of the synthetic resin base material 1 using the above-mentioned copolymer of polycarbonate and a monomer or polymer having Si atoms, the desired good bird dropping resistant contamination The light-transmitting bird provided with the easy-to-removable layer 2 for bird droppings, which has a low environmental impact due to the dehalogenating member, and has better translucency than fluororesin. It becomes possible to obtain a feces easy removal member, and it can also be used for applications requiring visibility. In addition, a copolymer of a polycarbonate and a monomer or polymer having an Si atom is generally less expensive than a fluorine-based resin, so that the cost can be reduced.
Even if it is a fluorine-based resin, when the easy-to-eat removal layer 2 is formed of, for example, polyvinylidene fluoride resin or polyvinyl fluoride resin, as shown in data of Comparative Examples 2 and 4 described later, the polar term γ _{Since the sp} ratio exceeds 8%, it is difficult to exhibit satisfactory resistance to bird droppings, which is not preferable.

Further, it is desirable that the bird dropping facilitating removal layer 2 contains an ultraviolet absorber. When the ultraviolet absorber is contained, the weather resistance is improved, so that the antifouling property against the bird droppings in the bird droppings removal layer 2 is effective. As the ultraviolet absorber, benzotriazole, triazine, benzophenone, or cyanoacrylate can be used. Moreover, as shown in the data of the examples described later, the value of the polar term of the surface free energy and the ratio occupied by the polar term are lower than those not containing the ultraviolet absorber, and the antifouling property against bird droppings (Anti-fouling resistance) is further improved, and there is an advantage that removal of bird droppings becomes easier. Examples of the ultraviolet absorber having the above effects include benzotriazole-based, triazine-based, and benzophenone-based ones.
The content of the ultraviolet absorber is not particularly limited, but it is appropriate to contain 1 to 15% by weight. If it is less than 1% by weight, there is almost no improvement in the resistance to bird droppings, and even if it is contained in a larger amount than 15% by weight, the effect of further improving the resistance to bird droppings cannot be obtained. It becomes useless.

  The thickness of the easy removal layer 2 is not particularly limited, but is suitably about 10 to 300 μm. By forming the bird dropping facilitating removal layer 2 having such a thickness, good bird dropping resistance can be exhibited over a long period without being worn in a short period.

  The bird droppings easy removal member having the above-described configuration is formed by coextruding the laminated constituent resin of the synthetic resin base material 1 and the molten constituent resin of the bird dropping easily removal layer 2 or by synthetic extrusion. The film or sheet for forming the easy removal layer 2 for bird droppings is applied to the surface of the synthetic resin substrate 1 by melt extrusion molding, or the film or sheet for forming the easy removal layer 2 for bird droppings is applied to the surface of the synthetic resin substrate 1 Lamination or transfer is performed, or a film or sheet for forming the easy removal of bird droppings 2 is bonded to the surface of the synthetic resin substrate 1 with an adhesive, or the easy removal of bird droppings layer 2 is applied to the synthetic resin substrate 1 It can be easily manufactured by adopting such a method. Moreover, you may perform processes, such as embossing, on the easy removal layer 2 of bird droppings.

In the bird dropping facilitation removal member of the present invention thus produced, the value of the polar term γ _sp of the surface free energy γ _s of the bird dropping facilitation removal layer 2 is 5.0 mJ / m ² or less, and the surface Since the ratio of the polar term γ _sp occupying the free energy γ _s is 8.0% or less, the adhesion of bird droppings due to the electroadsorption of albumin contained in the bird droppings is reduced. As shown, antifouling property against bird droppings (bird dropping resistance) is improved, and most of the attached bird droppings can be easily removed simply by flowing rainwater or tap water on the surface of the bird dropping removal layer 2. It becomes like this. Therefore, the bird excrement removal member of the present invention is suitably used for roofing materials, outer wall materials for houses, soundproof wall materials for highways, and other exterior uses.

In the method for removing bird droppings of the present invention, water is allowed to flow on the surface of the bird dropping removal layer 2 of the bird dropping removal member described above, and the bird droppings attached to the surface of the bird dropping removal layer 2 before flowing the water is removed. To be removed.
The method of flowing water is not particularly limited. For example, tap water or stored rainwater may be gently flown from the tip of the hose to the surface of the easy removal layer 2 or tap water or reservoir from the tip of the hose. Rainwater may be applied to the surface of the bird dropping removal layer 2 vigorously, tap water or water stored in the water can be sprayed on the surface of the bird dropping removal layer 2 The rain water that naturally falls on the surface of the feces easy removal layer 2 may be simply flowed.
In addition, it is desirable that the bird dropping facilitating removal member be inclined or set up so that the flowed water flows smoothly.
The amount of water to flow is not particularly limited, but is preferably at least equal to or greater than the amount of rainwater that falls naturally.

  If the method for removing bird droppings of the present invention is employed, for example, most of the bird droppings attached thereto are naturally removed by the rainwater that naturally falls on the bird dropping removal layer 2, so the bird droppings are intentionally removed. Even if the surface of the removal member is not cleaned, it is possible to prevent the bird droppings from remaining dirty and to reduce the aesthetics, the translucency, and the daylighting ability, thereby eliminating the need for cleaning.

  Next, examples and comparative examples of the bird excrement removal member according to the present invention will be described.

[Example 1]
As shown in [Table 2], polycarbonate siloxane copolymer (1) [SS1230 manufactured by Teijin Limited] 9.4% by weight, polycarbonate resin 84.9% by weight, and benzotriazole-based UV absorber A resin composition for forming an easy removal layer for bird droppings containing 5.7% by weight was prepared.
By coextrusion molding the polycarbonate resin containing the ultraviolet absorber for forming the synthetic resin base material heated and melted, and the above resin composition for forming the easy-to-removed layer of bird droppings by heating and melting, A translucent bird droppings easy removal member having a 50 μm thick bird droppings removal layer on the surface of a plate-shaped resin substrate having a thickness of 1.9 mm was prepared.

A small amount of water and hexadecane were dropped on the surface of the easy-to-removable layer of the easy-to-removable member of Example 1 and the respective contact angles were measured. As shown in Table 2 below, the contact with water The angle was 101.0 ° and the contact angle with hexadecane was 32.2 °.
Therefore, the surface free energy (γ _L , γ _Ld, γ _Lp ) of the water and hexadecane liquid described in [Table 1] and the numerical value of the contact angle described above are substituted into the equation [Formula 4], When the values of the surface free energy γ _s , the dispersion term γ _sd , and the polar term γ _sp of the easily removable layer 2 were calculated, the surface free energy γ _s was 24.4 mJ / m ² , as shown in Table 2 below. The term γ _sd was 23.5 mJ / m ² , the polar term γ _sp was 0.92 mJ / m ² , and the ratio of the polar term γ _sp to the surface free energy γ _s was 3.7%.

(Table 1) Surface free energy of liquid of water and hexadecane (unit: mJ / m ² )
┌────────┬────────┬────────┬────────┐
│ γ _L γ _Ld γ _Lp │
├────────┼────────┼────────┼────────┤
Water 72.8 21.8 51 │
├────────┼────────┼────────┼────────┤
Hexadecane 27.6 27.6 0 │
└────────┴────────┴────────┴────────┘

About the bird dropping facilitation removal member of this Example 1, the antifouling property (bird dropping excretion resistance) with respect to bird droppings was tested in the following manner.
First, 1 g of albumin (manufactured by Wako Pure Chemical Industries, Ltd., albumin, egg-derived) was dissolved in 9 g of distilled water to make a 10 wt% aqueous solution of albumin. Uric acid [Wako Pure Chemical Industries, Ltd.] (Product made, uric acid (Wako special grade)) 0.5g was mixed, and liquid pseudo bird droppings were prepared. Then, 0.5 mL of this artificial bird droppings is collected with a micropipette, and dropped on the surface of the bird dropping removal layer of the bird dropping removal member of Example 1, and then naturally dried for 24 hours to attach the dummy bird droppings. I let you.
Next, tap water is applied to the surface of the easy-to-removed layer of bird droppings on the surface of the bird droppings at a rate of 3.6 L / min. Was calculated as follows. That is, take pictures of the easy-to-removal layer of bird droppings before and after flowing water, and using software [Image J (public domain)] Measure the area of the artificial bird droppings remaining in the easy removal layer of the bird droppings after flowing the water, and determine the cleaning rate (removal rate) of the simulated bird droppings after flowing water from both areas. Contamination was evaluated.
As a result, the cleaning rate of the pseudo bird droppings of the bird dropping facilitating removal member of Example 1 is 84% as shown in [Table 2] described later, and the bird dropping contamination resistance evaluation is “◯” (good). there were. In addition, evaluation of bird dropping resistance was evaluated as “◯” (good) when the cleaning rate was 60% or more, and “X” (bad) when the cleaning rate was less than 60%.
Moreover, the translucent quality of the bird dropping facilitating removal member of Example 1 was visually evaluated and described in [Table 2] below. In this evaluation of translucency, “◯” indicates that the light can be clearly seen through, and “△” indicates that the light is not good and can be seen through but is unclear. Those not present were evaluated as “x”.

[Example 2-14]
In place of the easy-to-removal layer of the easy-to-removable member of Example 1, as shown in [Table 2] below, in Example 2, the polycarbonate-siloxane copolymer (1) was 28.3% by weight, An easy removal layer for bird droppings comprising 66% by weight of a polycarbonate resin and 5.7% by weight of a benzotriazole-based UV absorber [TINUVINE P manufactured by BASF Corp.] In Example 3, the polycarbonate-siloxane copolymer (1) An easy removal layer for bird droppings comprising 47.2% by weight of polycarbonate resin, 47.2% by weight of polycarbonate resin, and 5.7% by weight of a benzotriazole-based UV absorber. In Example 4, the polycarbonate-siloxane copolymer (1) An easy removal layer for bird droppings comprising 46.3% by weight, 46.3% by weight of a polycarbonate resin, and 7.4% by weight of a benzotriazole-based ultraviolet absorber, Carbonic acid-siloxane copolymer (1) 66% by weight, polycarbonate resin 28.3% by weight, benzotriazole ultraviolet absorber 5.7% by weight Easy removal layer of bird droppings comprising 48.1% by weight of siloxane copolymer (1), 48.1% by weight of polycarbonate resin, and 3.8% by weight of triazine UV absorber [TINUVINE 1577 manufactured by BASF Corp.] In Example 7, the easy removal layer of bird droppings made of the polycarbonate-siloxane copolymer (1), and in Example 8, 94.3% by weight of the polycarbonate-siloxane copolymer (1) and a benzotriazole-based ultraviolet absorber An easy removal layer of bird droppings composed of 5.7% by weight, in Example 9, polycarbonate siloxane copolymer (2) [SS made by Teijin Limited 525], a bird excrement removal layer made of a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer in Example 10, and a bird made of a tetrafluoroethylene / hexafluoropropylene copolymer in Example 11 Feces easy removal layer, Example 12 made of easy removal of bird droppings made of polytetrafluoroethylene resin, Example 13 made of easy removal of bird droppings made of tetrafluoroethylene resin, and Example 14 made of polychlorotrifluoroethylene resin Example 2 having a 50 μm thick easy-to-removable layer on the surface of a plate-shaped synthetic resin substrate having a thickness of 1.9 mm, in the same manner as in Example 1 except that each easy-to-removable layer was formed. -14 bird dropping easy removal member was produced.

About the bird dropping facilitation removal member of Example 2-14, the contact angle with water and the contact angle with hexadecane were measured in the same manner as in Example 1, and the surface free energy γ _s and the dispersion term γ of the bird dropping excretion removal layer were measured. The value of _sd and the polar term γ _sp and the ratio of the polar term γ _sp to the surface free energy γ _s were calculated. The results are shown in [Table 2] below.
Further, with regard to the easy removal of bird droppings of Example 2-14, the washing rate (removal rate) of the pseudo bird droppings adhered to the surface of the easy removal layer of bird droppings was obtained in the same manner as in Example 1, Contamination was evaluated. The results are shown in [Table 2] below.
In addition, with regard to the bird dropping facilitating member of Example 2-14, the light-transmitting quality was visually evaluated in the same manner as in Example 1, and the results are shown in Table 2 below.

[Comparative Example 1-7]
In place of the easy-to-removable layer of the feces-removing member of Example 1, as shown in [Table 2] below, in Comparative Example 1, the easy-to-removable layer made of polycarbonate resin, in Comparative Example 2, Easy removal layer of bird droppings made of vinylidene fluoride resin, in Comparative Example 3, easy removal layer of bird droppings made of a coating of fluorine-based paint [Defenser FH-700 manufactured by DIC Corporation], in Comparative Example 4, polyvinyl fluoride Easy removal layer of bird droppings made of resin, in Comparative Example 5, easy removal layer of bird droppings made of polypropylene resin, in Comparative Example 6, removal layer of bird droppings made of polymethyl methacrylate resin, and in Comparative Example 7, from polyethylene terephthalate resin Comparative Example 1 having a 50 μm thick easy-to-removable layer on the surface of a plate-shaped synthetic resin substrate having a thickness of 2 mm, except that each of the easy-to-removable layers was formed. 7's It was prepared Kusoeki removing member.

For the bird dropping facilitation removal member of Comparative Example 1-7, the contact angle with water and the contact angle with hexadecane were measured in the same manner as in Example 1, and the surface free energy γ _s and dispersion term γ of the bird dropping excretion removal layer were measured. The value of _sd and the polar term γ _sp and the ratio of the polar term γ _sp to the surface free energy γ _s were calculated. The results are shown in [Table 3] below.
Further, with regard to the easy removal of bird droppings of Comparative Example 1-7, the washing rate (removal rate) of pseudo bird droppings adhered to the surface of the easy removal layer of bird droppings was determined in the same manner as in Example 1, Contamination was evaluated. The results are shown in [Table 3] below.
In addition, about the bird dropping excretion removal member of the comparative example 1-7, the evaluation of translucency by visual observation was abbreviate | omitted.

  In the above [Table 2], PC represents polycarbonate and UVA represents an ultraviolet absorber.

From the above [Table 2], the value of the polar term γ _sp of the surface free energy γ _s of the bird dropping facilitating removal layer is 5.0 mJ / m ² or less and the polar term γ _sp occupies the surface free energy γ _s . The bird dropping facilitating removal member of Example 1-14 having a ratio of 8.0% or less has good pseudo bird dropping resistance (bird resistance) with a pseudo bird dropping cleaning rate (removal rate) of 60% or more. It can be seen that fecal contamination can be expressed.
On the other hand, as shown in [Table 3] above, the value of the polar term γ _sp of the surface free energy γ _s of the easy removal layer of bird droppings is larger than 5.0 mJ / m ² and the surface free energy γ _s. Even if the ratio of the polar term γ _sp occupying is less than 8.0%, the bird dropping easily removal member of Comparative Example 3-7 and the value of the polar term γ _sp is 5.0 mJ / m ² or less, the surface is free. The bird droppings easy removal member of Comparative Example 1-2 in which the ratio of the polar term γ _sp to the energy γ _s is greater than 8.0% has a cleaning rate (removal rate) of pseudo bird droppings of less than 60% or 0. It is understood that good pseudo-fouling resistance (bird dung resistance) cannot be expressed.

In addition, as shown in [Table 2], easy removal of bird droppings with a fluorine-based resin such as a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene / hexafluoropropylene copolymer, or a polytetrafluoroethylene resin. The easy-to-removal member for bird droppings of Example 10-12 in which the layer was formed exhibited an excellent pseudo bird dropping resistance with an extremely high washing rate of pseudo bird droppings of 90% or more. The bird droppings easy removal member of Examples 13-14 in which the layer for removing birds droppings is made of a fluorine-based resin such as coalescence, polychlorotrifluoroethylene resin, etc., also has a good anti-pseudo resistance with a pseudo bird dropping cleaning rate of 60% or more. Although the bird dropping property is expressed, the bird dropping removal member of Example 10-14 in which the bird dropping removal layer is formed of these fluororesins is inferior in translucency.
On the other hand, the bird dropping easily removal member of Example 1-9 in which the layer for removing bird droppings including a copolymer of polycarbonate and siloxane having Si atoms was formed had a cleaning rate of pseudo bird droppings of 80%. In addition to exhibiting good pseudo-bird excrement resistance in addition to the above, it also exhibits good translucency, so it can be used for applications that require visibility, so it has a high overall evaluation It is.
From this, it can be seen that a copolymer of a polycarbonate and a monomer or polymer having Si atoms is optimal as the constituent resin of the easy removal layer 2 for bird droppings.

  Further, as in Examples 1 to 6, the polycarbonate / siloxane copolymer and the polycarbonate resin are included, and the polycarbonate resin occupies 30 to 90 parts by weight with respect to 100 parts by weight of the constituent resin of the bird dropping removal layer 2. Even if the ratio which a polycarbonate resin occupies is large, the bird dropping easily removal member which formed the bird dropping easy removal layer (The bird dropping easy removal layer which polycarbonate resin occupies 28 to 85 weight% of the bird dropping easy removal layer 2) is pseudo. The cleaning rate (removal rate) of bird droppings is as high as 84% or more, and exhibits excellent pseudo bird dropping resistance. Therefore, the amount of the expensive polycarbonate / siloxane copolymer used can be suppressed by mixing a polycarbonate resin that is less expensive than the polycarbonate / siloxane copolymer, and thus there is a cost reduction effect.

In contrast to Examples 7 and 8, the constituent resin of the easy-to-removal layer of bird droppings is a polycarbonate / siloxane copolymer. Kusoeki removing member, as compared to bird droppings readily removable member of example 7 containing no ultraviolet absorber, the value of the polarity term gamma _sp of the surface free energy gamma _s, and polarity term occupying the surface free energy gamma _s gamma _{The sp} ratio is reduced, the washing rate of the pseudo bird droppings is increased, and the pseudo bird dropping resistance is improved.
From this, it can be seen that inclusion of an ultraviolet absorber in the bird dropping facilitating removal layer is extremely effective in further improving the resistance to pseudo bird droppings. Furthermore, it has the effect that the antifouling property of bird droppings is maintained by improving the weather resistance.

1 Synthetic resin base material 2 Bird droppings easy removal layer

Claims (4)

A bird droppings removal member having a synthetic resin substrate and a bird droppings removal layer formed on the surface thereof, wherein the value of the polar term of the surface free energy of the bird droppings removal layer is 5.0 mJ / m ² or less And the ratio of the polar term in the surface free energy is 8.0% or less.   The bird dropping easily removing member according to claim 1, wherein the bird dropping easily removing layer includes a copolymer of a polycarbonate and a monomer or polymer having Si atoms.   The bird dropping easily removal member according to claim 1 or 2, wherein the bird dropping easy removal layer contains an ultraviolet absorber.   A large amount of bird droppings adhering to the surface of the easy-to-removal layer of the bird droppings before flowing water on the surface of the easy-to-removing layer of bird droppings of the bird dropping removal member according to any one of claims 1 to 3 A method for removing bird droppings, comprising removing a portion.

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