JP4060231B2 - Structure for suppressing temperature rise in buildings - Google Patents

Description

【００４３】
式中のＲ_１は、メチル基、エチル基、Ｒ_２、Ｒ_３は、メチル基、エチル基またはＲ_４で示される基、Ｒ_４は−Ｒ_５（ＣＨ_２ＣＨ_２Ｏ）_ａ（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_ｂＲ_６（Ｒ_５は、例えば、アルキレン基（好ましくは炭素数１〜３）等が挙げられる。Ｒ_６は、例えば、メチル基、エチル基、プロピル基、ブチル基などの炭素数１〜１２のアルキル基、シクロヘキシル基などの炭素数６〜１２のシクロアルキル基、ビニル基、アリル基などの炭素数２〜８のアルケニル基、フェニル基、トリル基などの炭素数６〜１２のアリール基、ベンジル基、フェニルエチル基などの炭素数７〜１２のアラルキル基、及びこれらの基の水素原子の少なくとも一部をハロゲン原子、シアノ基などで置換した基、例えばクロロメチル基、トリフロロプロピル基、シアノエチル基等が挙げられる。ａ及びｂはそれぞれ０〜２０の整数であり、ａ＋ｂ≧１である。）、ｎ及びｍはそれぞれ０〜１００の整数であり、但しｎ＝０の時は、Ｒ_２及び／又はＲ_３はＲ_４とする。
【００４４】
（ｔ）成分は、（ｐ）成分の固形分１００重量部に対して、０．０５〜１５重量部、好適には０．３〜５重量部配合することが望ましい。０．０５重量部未満では濡れ性向上効果が得られ難く、塗装作業性に劣る場合があり、１５重量部を超えると、建築物外装面や上塗層との密着性に悪影響を与えるおそれがある。
【００４５】
下塗材組成物においては、上述の成分に加え、さらに、アルコキシシラン化合物を含有することもできる。アルコキシシラン化合物は、下塗層被膜の形成途上において被膜の表面に局在化し、上塗層との密着性向上に寄与することができるものであり、例えば、被膜表面への局在化のしやすさ等の点から、炭素数が１〜２のアルコキシル基と、炭素数が３以上のアルコキシル基を含有するアルコキシシランの縮合物、または、繰り返し単位の炭素数が１〜４のポリオキシアルキレン基と、炭素数が１〜４のアルコキシル基を含有するアルコキシシランの縮合物等を挙げることができる。
【００４６】
下塗材組成物においては、上記成分の他、各種の添加剤、例えば、顔料、骨材、繊維、増粘剤、レベリング剤、可塑剤、防腐剤、防黴剤、防藻剤、抗菌剤、分散剤、消泡剤、紫外線吸収剤、酸化防止剤等を含むこともできる。
【００４７】
【発明の実施の形態】
以下、本発明の実施形態について説明する。
【００４８】
本発明は、建築物外装面の表面に形成された被膜、及び該被膜表面に水を供給する手段を備えるものである。本発明は、主に、屋根、屋上、外壁などの建築物外装面に適用することができる。図１は、その一例として、建築物の屋根に本発明の温度抑制構造を適用した例を示すものである。
【００４９】
本発明において、水を供給する手段としては、被膜表面に水が供給可能なものである限り、各種の手段を用いることができる。
図１では、給水源２からポンプ３にて水を汲み上げ、屋根の頂部に設けたノズル４から散水する装置等が設けられている。
ここで、給水源２としては、例えば、貯水槽、井戸、水道管等を使用することができる。環境への負荷低減、コスト等を考慮すると、雨水の収集構造を備えた貯水槽等が好適である。
給水源２、ポンプ３、及びノズル４の連結には給水管５を用いればよい。また、給水管５には水の供給量を調節するための流量調整弁を適宜設けることもできる。
屋根から流下した水は、貯水槽等に回収することにより再利用することもできる。
建築物の壁面に水を供給する場合は、壁面上部等にノズル４が配置されるようにすればよい。その他の構成は、図１と同様のものを用いることができる。
【００５０】
図２は、基材６の上に設けられた積層被膜７を示す図である。
基材６としては、特に限定されず、例えば、コンクリート、モルタル、繊維混入セメント板、セメント硅酸カルシウム板、スラグセメントパーライト板、石綿セメント板、軽量コンクリート板、サイディングボード、押出し成形板、亜鉛めっき鋼板、亜鉛−鉄合金めっき鋼板、亜鉛−アルミ合金めっき鋼板、アルミめっき鋼板、クロムめっき鋼板、ニッケルめっき鋼板、亜鉛−ニッケル合金めっき鋼板、錫めっき鋼板、ステンレス鋼板、アルミめっきステンレス鋼板、鉛めっきステンレス鋼板、亜鉛めっきステンレス鋼板等が挙げられる。
【００５１】
本発明における下塗層８は、水蒸気吸脱着性を有し、その水蒸気吸脱着性がヒステリシス特性を示すものである。
ここで水蒸気吸脱着性のヒステリシス特性とは、図３に示すように、相対湿度を横軸に、水蒸気吸脱着量を縦軸にとった場合の吸脱着等温線で、吸着曲線より脱離曲線が上側になることを意味するものである。なお、この吸脱着等温線は、温度を一定（２５℃に設定）として相対湿度を低い状態から高い状態へ順次上げた後、再び低い状態へ戻すことによって得られ、下塗層８が単位重量当りに保持可能な水蒸気量を表すものである。
具体的には、まず温度２５℃、相対湿度４０％の恒温恒湿器内に下塗層の重量が平衡になるまで放置し、放置後の重量を測定する。次に同温度で湿度のみを上昇させた恒温恒湿器内で同様の操作を行い、順次段階的に湿度のみを上げながら相対湿度９０％まで測定を行う。その後、同温度下で湿度のみを段階的に下げながら同様の操作を繰り返し、重量を測定する。このような測定により得られる各湿度における下塗層８の重量から水蒸気吸脱着量を算出することにより、水蒸気吸脱着性を示す吸脱着等温線を得ることができる。
【００５２】
本発明では、このような水蒸気吸脱着性を有することにより、大気中の水分を吸着した下塗層８が、温度の上昇とともにその水分を脱離し、その際、水の気化潜熱により下塗層８から熱が奪われるため、温度の上昇を抑えることができる。さらに、このヒステリシス特性によって、夜間等の温度の低い状態において大気中の水分を吸着し、温度が上昇する日中に脱離による温度上昇の抑制効果を発揮することができる。下塗層８が温度上昇抑制効果を発揮している間は、被膜表面に対する水の供給を行わなくてもよい。
【００５３】
下塗層８は、（ｐ）結合剤、（ｑ）多孔質無機粉体を含有する下塗材組成物によって形成される。（ｑ）成分は、下塗層にヒステリシス特性を付与するために有効にはたらく成分であり、（ｑ）成分を含有することにより、水の気化潜熱による温度上昇抑制効果を長時間保持することが可能となる。下塗材組成物においては、（ｐ）、（ｑ）成分に加え、（ｒ）吸放湿性合成樹脂微粒子を含有することが望ましい。（ｒ）成分を含有することにより、水蒸気吸脱着量を増加させ、水蒸気吸脱着速度を高めることができる。さらに、下塗材組成物に架橋剤（（ｓ）成分）が含まれることにより、下塗層８の強度及び水蒸気吸脱着性を向上させることが可能となる。
【００５４】
建築物外装面の最表面には、被膜表面の水に対する接触角が７０°以下である上塗層９が形成される。このような上塗層９は、親水性が高く保水性能にも優れることから、上塗層９の表面に水を供給すると、その供給量が少量であっても水が上塗層の面に十分に濡れ広がる。そして、水が蒸発する際の気化潜熱によって建築物の温度上昇を抑制することができる。また、水の供給によって上塗層９の全体に水が濡れ広がることにより、下塗層８に均一に水分を補給することも可能となる。
上塗層９の水に対する接触角は、７０°以下であることが必要であるが、望ましくは５０°以下、さらに望ましくは３０°以下である。
【００５５】
上塗層９は、（ａ）テトラアルコキシシラン化合物、（ｂ）触媒、（ｃ）水、（ｄ）溶剤、及び（ｅ）第４級カチオン塩基含有重合体を混合して得られる上塗材組成物により形成される。このような上塗材組成物によって形成される上塗層９は、十分な水蒸気透過性を有するため、下塗層８の水蒸気吸脱着性を阻害しない。
【００５６】
基材６に被膜を形成する際には、まず下塗材組成物を塗付する。下塗材組成物は、基材６に対して直接塗付してもよいし、何らかの表面処理（シーラー、サーフェーサー、フィラー等による下地処理等）を施した後に塗付してもよい。既に被膜が形成された基材に適用することも可能である。下塗材組成物を塗付する際には、例えば、スプレー、ローラー、刷毛等を用いることができる。工場等でプレコートを行う場合は、ロールコーター、フローコーター等を用いることもできる。
下塗層８が形成された後、上塗材組成物を塗付積層する。上塗材組成物においては、紙、布、不織布等に含浸して拭き塗りする方法等の方法により塗付することができる。この他、スプレー、ローラー、刷毛、ロールコーター、フローコーター等を用いて塗付することもできる。
形成される層の膜厚は、通常、下塗層が５〜１５０μｍ程度、上塗層が０．０１〜１０μｍ程度である。
【００５７】
積層被膜７について性能試験を行った結果を以下に示す。
【００５８】
図４は、各種下塗材組成物によって形成された下塗層について、水蒸気吸脱着性を測定したものである。
下塗層Ａ〜Ｅは、それぞれ下塗材組成物Ａ〜Ｅをアルミ板上に乾燥膜厚が５００μｍとなるように塗付形成したものである。なお、下塗材組成物Ａ〜Ｅは、表１に示した原料を使用して、表２に示した比率に従って各原料を混合することにより製造した。
【００５９】
【表１】

【００６０】
【表２】

【００６１】
図５は、下塗層に上塗層を積層した被膜の水蒸気吸脱着性を示すものである。積層被膜Ａ〜Ｅは、それぞれ下塗層Ａ〜Ｅに上塗材組成物Ａを乾燥膜厚が０．５μｍとなるように塗付形成したものである。
なお、上塗材組成物Ａとしては、テトラメトキシシランの部分加水分解縮合物（平均分子量５００、ＳｉＯ_２比率５１重量％）をＳｉＯ_２換算で１００重量部用意し、これにアルミニウムトリス（アセチルアセトネート）を０．５重量部、エタノールを５４００重量部、及び水を７５００重量部混合して約３０分間攪拌した後、さらに第４級カチオン塩基含有重合体（メチルアクリレート−エチルアクリレート−ポリグリセロールジアクリレート−ジメチルアミノエチルメタクリレート４級化物の共重合体水溶液、全単量体中のジメチルアミノエチルメタクリレート４級化物の比率２８重量％、固形分３０重量％）を固形分換算で１３重量部均一に混合することにより得られたものを使用した。この上塗材組成物Ａにより形成される被膜の水に対する接触角を、ＣＡ−Ａ型接触角測定装置（協和界面科学株式会社製）にて測定（測定温度２３℃）したところ、２５°であった。
【００６２】
積層被膜Ｆは、下塗層Ａに上塗材組成物Ｂを乾燥膜厚が０．５μｍとなるように塗付形成したものである。
なお、上塗材組成物Ｂとしては、テトラメトキシシランの部分加水分解縮合物（平均分子量５００、ＳｉＯ_２比率５１重量％）をＳｉＯ_２換算で１００重量部用意し、これにアルミニウムトリス（アセチルアセトネート）を０．５重量部、エタノールを５４００重量部、及び水を７５００重量部混合して約３０分間攪拌し、次いで、第４級カチオン塩基含有重合体（メチルアクリレート−エチルアクリレート−ポリグリセロールジアクリレート−ジメチルアミノエチルメタクリレート４級化物の共重合体水溶液、全単量体中のジメチルアミノエチルメタクリレート４級化物の比率２８重量％、固形分３０重量％）を固形分換算で１３重量部混合し、さらにシリカゾル（固形分３０重量％、粒子径１０〜２０ｎｍ、分散媒：イソプロピルアルコール）を固形分換算で１００重量部混合することにより得られたものを使用した。この上塗材組成物Ｂにより形成される被膜の水に対する接触角を、ＣＡ−Ａ型接触角測定装置（協和界面科学株式会社製）にて測定（測定温度２３℃）したところ、２３°であった。
【００６３】
積層被膜Ｇは、下塗層Ａに上塗材組成物Ｃを乾燥膜厚が３０μｍとなるように塗付形成したものである。なお、上塗材組成物Ｃとしては、溶剤可溶形アクリル樹脂（メチルメタクリレート・ブチルアクリレート・酢酸ビニル共重合体、不揮発分５０重量％）からなるものを使用した。この上塗材組成物Ｃにより形成される被膜の水に対する接触角を、ＣＡ−Ａ型接触角測定装置（協和界面科学株式会社製）にて測定（測定温度２３℃）したところ、８３°であった。
【００６４】
図４、図５より明らかなように、（ａ）〜（ｅ）成分を含む上塗材組成物Ａにより形成された上塗層は、下塗層の水蒸気吸脱着性を阻害しないものである。また、（ａ）〜（ｆ）成分を含む上塗材組成物Ｂにより形成された上塗層も、下塗層の水蒸気吸脱着性を阻害しないものである。
【００６５】
図６は、積層被膜Ａ〜Ｇについて、遮熱試験を行った結果である。
この遮熱試験は、まず、温度２５℃、相対湿度９０％の恒温恒湿器内に各試験体の重量が平衡になるまで放置し、次に、２５０Ｗの赤外線ランプを用いて、赤外線を積層被膜表面に３６０分間照射し、基材の裏面温度を測定する方法にて行った。
図６より、積層被膜Ａ〜Ｄ、及び積層被膜Ｆは、優れた温度上昇抑制効果を示すことが認められた。積層被膜Ｅ、Ｇは、水蒸気吸脱着性が低く、遮熱試験における温度上昇が著しかった。
【００６６】
図７、８は、積層被膜に対し水を供給した際の被膜表面の濡れの状況を示す図である。積層被膜Ａ、積層被膜Ｆについては、図７に示すように供給された水が広範に濡れ広がり、均一な水膜が形成された。これに対し、積層被膜Ｇでは、図８に示すようにノズルから供給された水が筋状に流れ落ちてしまった。
水供給時における各積層被膜の温度上昇抑制効果を確認するため、乾燥状態にある各積層被膜に対し赤外線ランプを３０分照射した後、ノズルから一定量の水を供給し、この際の基材の裏面温度変化を測定した。その結果、積層被膜Ａでは水供給によって温度を１８℃下げることができた。積層被膜Ｆでは２０℃下げることができた。これに対し、積層被膜Ｇでは１０℃下げるに留まった。
【００６７】
一方、上述の下塗材組成物Ａにポリエーテル変性ポリシロキサン化合物０．２５重量部を添加することにより、下塗材組成物Ｈを製造した。この下塗材組成物Ｈをアルミ板上に乾燥膜厚が５０μｍとなるように塗付形成し、次いで上塗材組成物Ａを乾燥膜厚が０．５μｍとなるように塗付形成し、積層被膜Ｈを得た。この際、下塗材組成物Ｈ、上塗材組成物Ａの塗装において、垂れやはじき等はみられず、均一で平滑な塗膜を容易に形成することができた。積層被膜Ｈについては、水蒸気脱着性試験、遮熱性試験において積層被膜Ａと同等の結果が得られた。
【００６８】
【発明の効果】
本発明では、建築物外装面の被膜において特定の下塗層を設けている。この下塗層は、大気中の水分を自律的に吸着することができ、その水分が気化する際の気化潜熱により、建築物の温度上昇を抑制することができる。このため、下塗層が水分の脱離による温度上昇抑制効果を発揮している間は、水の供給を行わなくてもよい。
一方、被膜の最表面には、親水性が高い特定の上塗層を設けているため、水を供給した際には、水の量が少量であっても広範に濡れ広がり、効率的な冷却を行うことができる。
また、被膜表面における水の供給によって、下塗層に均一に水分を補給することもできる。この水分補給により、再び下塗層による冷却効果が発揮される。
本発明では、このような下塗層及び上塗層の相互作用により、建築物内部の温度上昇を効率的に抑制し、夏季における冷房使用を減らすことができる。また、近年問題となっているヒートアイランド現象を抑制することもできる。
【図面の簡単な説明】
【図１】本発明の実施態様の一例を示す図
【図２】本発明の積層被膜の断面を示す図
【図３】ヒステリシス特性を示す図
【図４】水蒸気吸脱着性を示すグラフ（下塗層Ａ〜Ｅ）
【図５】水蒸気吸脱着性を示すグラフ（積層被膜Ａ〜Ｇ）
【図６】遮熱試験を示すグラフ（積層被膜Ａ〜Ｇ）
【図７】水供給時の状況を示す図（積層被膜Ａ、Ｆ）
【図８】水供給時の状況を示す図（積層被膜Ｇ）
【符号の説明】
１：建築物
２：給水源
３：ポンプ
４：ノズル
５：給水管
６：基材
７：積層被膜
８：下塗層
９：上塗層
１０：水[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for suppressing a temperature rise of a building by supplying water to the surface of an exterior surface coating such as a roof, a roof, or an outer wall of the building.
[0002]
[Prior art]
In recent years, urban climates have been created in urban areas by artificial radiant heat exhausted from concrete buildings and air conditioning. Especially in summer, the outdoor temperature rise in urban areas is remarkable, causing a problem called the heat island phenomenon. On the other hand, in buildings, the indoor temperature is often lowered by using cooling, but the heavy use of cooling not only increases the power consumption energy but also increases the outdoor temperature by exhausting from the outdoor unit. Is conducive.
[0003]
As a method for suppressing the temperature rise of a building, for example, there is a method of applying a coating material or the like disclosed in JP-A-6-1000079. However, such a method may not always provide a sufficient temperature rise suppression effect.
As another method for suppressing the temperature rise of the building, for example, as disclosed in JP-A-4-186030, there is a method of cooling the roof with the latent heat of vaporization by watering the roof. However, simply providing a watering structure as described in the publication will not allow an efficient cooling effect because the water will flow down in a short time, and the water supplied to the roof surface The problem is that the entire roof cannot be cooled uniformly because it flows down in the form of streaks.
[0004]
[Problems to be solved by the invention]
This invention is made | formed in view of such a point, and it aims at providing the method which can fully suppress the temperature rise of a building.
[0005]
[Means for Solving the Problems]
As a result of intensive studies, the inventor has adopted a structure having a specific laminated coating formed on the surface of the building exterior surface and means for supplying water to the coating surface, thereby increasing the temperature of the building. The inventors have found that it can be sufficiently suppressed and completed the present invention.
[0006]
That is, the present invention has the following characteristics.
1. A temperature rise suppressing structure of a building comprising a coating formed on the surface of a building exterior surface, and means for supplying water to the coating surface, the coating comprising:
(P) An undercoat layer formed of an undercoat material composition obtained by mixing a binder, (q) a porous inorganic powder, and (t) a polyether-modified polysiloxane compound, and having a water vapor adsorption / desorption property having hysteresis characteristics,as well as
(A) a tetraalkoxysilane compound, (b) a catalyst, (c) water, (d) a solvent, and (e) a coating composition formed by mixing a quaternary cation base-containing polymer. A structure for suppressing temperature rise of a building, comprising a top coat layer having a surface contact angle with water of 70 ° or less.
2. Undercoat layer
(P) 100 parts by weight of binder in solids,
(Q) 10 to 600 parts by weight of a porous inorganic powder,
(T) 0.05 to 15 parts by weight of a polyether-modified polysiloxane compound
1. It is formed by the primer composition which contains. The structure for suppressing temperature rise of a building as described in 1.
3. 1. The undercoat material composition further comprises 2 to 100 parts by weight of (r) hygroscopic synthetic resin fine particles. The structure for suppressing temperature rise of a building as described in 1.
4). In the primer composition, (p) includes a reactive functional group-containing synthetic resin binder, (r) is a reactive functional group-containing hygroscopic synthetic resin fine particle,
(S) A crosslinking agent having a functional group capable of reacting with the functional group
1. It is characterized by containing 2. Or 3. The structure for suppressing temperature rise of a building as described in 1.
5. The topcoat layer is formed by a topcoat composition obtained by mixing (f) a metal oxide sol with a particle size of 3 to 100 nm in addition to the components (a) to (e). 1. ~ 4. The temperature rise suppression structure of the building as described in any of the above.
[0007]
Here, the topcoat material composition for forming the topcoat layer will be described.
The topcoat composition is obtained by mixing (a) a tetraalkoxysilane compound, (b) a catalyst, (c) water, (d) a solvent, and (e) a quaternary cation base-containing polymer. The formed film can exhibit sufficient hydrophilicity.
Examples of the (a) tetraalkoxysilane compound (hereinafter referred to as “component (a)”) include, for example, tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, and tetraisobutoxy. Examples thereof include silane, tetra sec-butoxy silane, tetra t-butoxy silane, tetraphenoxy silane, dimethoxydiethoxy silane, and the like, and condensates thereof. Among these, as a component (a) in this invention, tetramethoxysilane and / or its condensate are used suitably.
[0008]
In the top coating composition, an alkoxysilane compound other than the component (a) can be used in combination. Examples of such alkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, methyltri Roroshiran like, or their condensates thereof. Moreover, the alkoxysilane compound containing a carboxyl group, a hydroxyl group, a sulfone group, an oxyalkylene group etc. can also be used.
[0009]
(B) The catalyst (hereinafter referred to as “component (b)”) is a component that acts on the hydrolysis reaction of component (a). Specifically, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; organic acids such as acetic acid, benzenesulfonic acid and toluenesulfonic acid; alkaline catalysts such as sodium hydroxide, potassium hydroxide, ammonia and amine compounds Organic organo compounds such as dibutyltin dilaurate, dibutyltin dioctate and dibutyltin diacetate; organoaluminum compounds such as aluminum tris (acetylacetonate) and aluminum monoacetylacetonate bis (ethylacetoacetate); titanium tetrakis (acetylacetonate) Organic zirconium compounds such as zirconium tetrakis (cetylacetonate); boron compounds such as boric acid, and the like.
[0010]
The mixing amount of the component (b) is the SiO content of the component (a)₂It is 0.1-10 weight part with respect to 100 weight part of conversion amount, Preferably it is 0.5-5 weight part. When the component (b) is less than 0.1 part by weight, the hydrophilicity of the formed film may not be sufficiently exhibited. If the amount exceeds 10 parts by weight, it is not possible to expect an effect corresponding to the mixing amount.
[0011]
In addition, SiO₂Conversion refers to silica (SiO 2) when a compound having an Si—O bond such as an alkoxysilane compound is completely hydrolyzed and then baked at 900 ° C.₂) And the remaining weight.
In general, an alkoxysilane compound or the like reacts with water to cause a hydrolysis reaction to form silanol, and further has a property of causing a condensation reaction between silanols or between silanol and alkoxy. When this reaction is performed to the ultimate, silica (SiO₂) These reactions are
RO (Si (OR)₂O)_nR + (n + 1) H₂O → nSiO₂+ (2n + 2) ROH
(R represents an alkyl group. N is an integer.)
The amount of the remaining silica component is converted based on this reaction equation.
[0012]
(C) The mixing amount of water (hereinafter referred to as “component (c)”) is the SiO content of component (a).₂The amount is 100 to 50000 parts by weight, preferably 500 to 10000 parts by weight with respect to 100 parts by weight of the conversion amount. With such a mixing amount, the condensation reaction of the silanol group of the component (a) generated from the reaction with the component (c) is suppressed, and the formed coating can exhibit sufficient hydrophilicity. When the mixing amount of the component (c) is less than 100 parts by weight, it is difficult to ensure the storage stability of the top coating composition, and the hydrophilic expression effect in the formed film is also reduced. When the amount is more than 50000 parts by weight, it is difficult to obtain a hydrophilic expression effect in the formed film.
[0013]
(D) Solvent (hereinafter referred to as “component (d)”) includes, for example, alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol, propylene glycol monomethyl ether, diethylene glycol In addition to glycol derivatives such as monoethyl ether and ethylene glycol monoethyl ether acetate, hydrocarbons, esters, ketones, ethers and the like can be mentioned. Among these, at least one selected from methanol, ethanol, isopropanol, propylene glycol monomethyl ether, and diethylene glycol monoethyl ether is preferably used from the viewpoint of the storage stability of the top coating composition and the hydrophilicity of the formed film.
The mixing amount of component (d) is the SiO content of component (a).₂The amount is 100 to 50000 parts by weight, preferably 500 to 10000 parts by weight with respect to 100 parts by weight of the conversion amount. When the amount is less than 100 parts by weight, it is difficult to uniformly dissolve the components (a), (b), and (c) described above. When the amount is more than 50000 parts by weight, it is difficult to obtain a hydrophilic expression effect in the formed film.
[0014]
In the topcoat composition of the present invention, (e) a quaternary cation base-containing polymer (hereinafter referred to as “component (e)”) is contained as an essential component, so that no repelling or the like occurs during coating, It becomes possible to apply uniformly to the coating surface. Furthermore, the component (e) is also preferable in terms of the hydrophilicity of the formed film. Therefore, in the present invention, a stable cooling effect can be obtained by including the component (e) in the top coating composition.
[0015]
Examples of the quaternary cation base in component (e) include quaternary ammonium bases, quaternary imidazolium bases, and quaternary phosphonium salts. Among these, a quaternary ammonium base is particularly preferable.
[0016]
The component (e) can be obtained by using (l) a quaternary cation base-containing monomer (hereinafter referred to as “(l) component”) as a monomer component constituting the polymer. In addition, (m) a monomer capable of generating a quaternary cation base (hereinafter referred to as “component (m)”) is used to obtain a polymer, and then the functional group of component (m) is quaternized. Can also be obtained.
The component (l) can be obtained by previously quaternizing the component (m) before polymerization.
[0017]
The component (e) may be a component obtained by copolymerizing the component (l) and / or the component (m) together with (n) another monomer copolymerizable with these (hereinafter referred to as “component (n)”). Alternatively, it may be a polymer composed of only the component (l) and / or the component (m).
The component (l) and the component (m) are 3% by weight or more in total (preferably 10% by weight or more and 100% by weight or less, more preferably 15% by weight or more and 80% by weight) in the monomer component constituting the component (e). % Or less, most preferably 20 wt% or more and 50 wt% or less). If it is such a ratio, the more outstanding effect can be acquired in the point of repellency prevention property and hydrophilic property provision.
[0018]
As the component (l), those having a quaternary cation base and a polymerizable unsaturated bond can be used. Among these, as the quaternary ammonium base-containing monomer, for example, dimethylaminoethyl acrylate quaternized product, diethylaminoethyl acrylate quaternized product, dimethylaminoethyl methacrylate quaternized product, diethylaminoethyl methacrylate quaternized product, methylethylamino acrylate Quaternized products, methylethylaminoethyl methacrylate quaternized products, dimethylaminostyrene quaternized products, diethylaminostyrene quaternized products, methylethylaminostyrene quaternized products and the like can be mentioned. These can be used alone or in combination of two or more.
[0019]
As the component (m), those having a functional group capable of generating a quaternary cation base by quaternization and a polymerizable unsaturated bond can be used. Among these, examples of monomers capable of producing a quaternary ammonium base include, for example, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methylethylaminoacrylate, methylethylaminoethyl methacrylate, dimethylamino. Examples thereof include styrene, diethylaminostyrene, methylethylaminostyrene and the like. These can be used alone or in combination of two or more.
[0020]
The quaternization of the component (m) may be performed by a known method. Examples of the quaternizing agent include benzyl chloride, methyl chloride, ethyl chloride, methyl bromide, methyl iodide, diethyl sulfate, dimethyl sulfate, methyl toluenesulfonate, ethyl toluenesulfonate, methyl methanesulfonate, and methanesulfonic acid. And ethyl.
[0021]
The component (n) is not particularly limited as long as it is a monomer copolymerizable with the components (l) and (m). Specifically, for example, acrylic acid or alkyl ester of methacrylic acid such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate; acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc. Carboxyl group-containing monomers; hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, polyglycerol diacrylate and polyglycerol dimethacrylate; vinyl ester monomers such as vinyl acetate and vinyl propionate; acrylonitrile, methacrylonitrile Nitrile group-containing monomers such as styrene; aromatic monomers such as styrene, 2-methylstyrene, vinyltoluene and divinylbenzene; Amide group-containing monomers such as methacrylamide, maleic acid amide, N-methylol acrylamide, diacetone acrylamide; carbonyl group-containing monomers such as acrolein, diacetone acrylamide, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone; be able to.
[0022]
The mixing amount of component (e) is the SiO content of component (a).₂It is 1 to 100 parts by weight, preferably 5 to 50 parts by weight in terms of solid content with respect to 100 parts by weight of conversion. When the amount of the component (e) is less than 1 part by weight, it is difficult to uniformly coat and form a film. When the amount is more than 100 parts by weight, the physical properties of the film such as water resistance may be adversely affected.
[0023]
In the top coating composition of the present invention, in addition to the components (a) to (e) described above, (f) a metal oxide sol having a particle diameter of 3 to 100 nm (hereinafter referred to as “(f) component”) is included. Is desirable. By blending the component (f), the hydrophilicity of the formed film can be further increased.
[0024]
Such component (f) is a colloidal solution in which colloidal particles made of a metal oxide are dispersed in a solvent.
Examples of the metal component in component (f) include silicon, aluminum, titanium, zirconium, antimony, magnesium, and the like. Among these, silica sol in which the metal component is silicon is preferable.
As the solvent, water and / or an organic solvent can be used, but an organic solvent is preferable in terms of storage stability and the like. Specific examples of the organic solvent include methanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, ethylene glycol, ethyl cellosolve, dimethylacetamide and the like.
The particle size of the component (f) is 3 to 100 nm, desirably 5 to 80 nm. When the particle size of the component (f) is too small, it is difficult to obtain the effect of improving hydrophilicity, and when the particle size is too large, the sharpness of the film may be impaired. The particle diameter in the present invention is a value measured by a dynamic light scattering method.
[0025]
The mixing amount of the component (f) is the SiO content of the component (a).₂It is 5 to 1000 parts by weight, preferably 10 to 300 parts by weight, in terms of solid content, with respect to 100 parts by weight of conversion. With such a mixing amount, a sufficient hydrophilicity improving effect can be obtained.
[0026]
In the topcoat composition of the present invention, in addition to the above-mentioned components, for example, resins, pigments, dyes, thickeners, leveling agents, wetting agents, plasticizers, preservatives, antifungal agents, antialgae agents, antibacterial agents , Surfactants, antifoaming agents, ultraviolet absorbers, antioxidants, and the like can also be mixed. Examples of the resin include resins other than the above-described component (e). Specifically, for example, an acrylic resin, a polyester resin, a polyvinyl alcohol resin, a butyral resin, an amino resin, a urethane resin, a silicone resin, a fluororesin, or a resin in which these are combined can be given. Among these, what has a hydroxyl group, a carboxyl group, an alkoxyl group etc. as a functional group in resin can also provide the reactivity with (a) component, for example.
Examples of pigments include inorganic color pigments such as titanium oxide, zinc oxide, carbon black, ferric oxide, yellow iron oxide, ultramarine, and cobalt green, azo, naphthol, perylene, quinacridone, and benzimidazole. Organic pigments such as phthalocyanine, heavy pigments such as calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, and diatomaceous earth can be used. However, it is desirable to avoid the use of a component having a photocatalytic function because there is a risk of deterioration of adhesion over time, fading of the colored coating, corrosion of the metal substrate, reduction of the photocatalytic action, and the like.
[0027]
Next, the primer composition for forming the primer layer will be described.
The undercoat layer in the present invention has water vapor adsorption / desorption properties, and can be formed from an undercoat material composition containing (p) a binder and (q) porous inorganic powder.
[0028]
Specifically, it is desirable to use (p-1) a synthetic resin binder and / or (p-2) an inorganic binder as the (p) binder (hereinafter referred to as “(p) component”).
[0029]
Examples of (p-1) synthetic resin binder (hereinafter referred to as “(p-1) component”) include, for example, ethylene resin, vinyl acetate resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, Any of water-based and solvent-based resins such as silicon resin, fluororesin, etc., or a composite system of these can be used. In particular, the use of one or more resins selected from acrylic resins, urethane resins, silicon resins, and fluororesins can increase durability, and the use of epoxy resins can increase adhesion.
By using the component (p-1), a flexible undercoat layer can be obtained. The degree of flexibility can be freely changed by adjusting the glass transition temperature of the resin.
[0030]
(P-2) Examples of the inorganic binder (hereinafter referred to as “(p-2) component”) include, for example, Portland cement, blast furnace cement, silica cement, fly ash cement, white cement, calcined gypsum, colloidal silica, and water solubility. Examples thereof include alkali metal silicates, and one or more of these can be used.
By using the component (p-2), the thickness of the undercoat layer can be increased. It is also possible to ensure high water vapor adsorption / desorption performance.
[0031]
When the component (p-1) is included as a binder, the component (p-1) is preferably a reactive functional group-containing synthetic resin binder. As the reactive functional group of the component (p-1), those capable of reacting with the functional group of the crosslinking agent described later can be used. Examples of such functional group combinations include, for example, carboxyl group and metal ion, carboxyl group and carbodiimide group, carboxyl group and epoxy group, carboxyl group and aziridine group, carboxyl group and oxazoline group, hydroxyl group and isocyanate group, and carbonyl group. Examples include hydrazide groups, epoxy groups and amino groups.
[0032]
In the present invention, a carboxyl group is particularly preferably used as the reactive functional group of the component (p-1). Examples of carboxyl group-containing synthetic resin binders include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and fumaric acid, and ammonium salts, organic amine salts, and alkali metals. It can be obtained by copolymerizing a carboxyl group-containing monomer such as a salt. These monomers can be used alone or in combination of two or more.
[0033]
(Q) As the porous inorganic powder (hereinafter referred to as “(q) component”), for example, a porous inorganic powder of clay minerals such as silica gel, zeolite, sodium sulfate, alumina, activated carbon, and allophane is used. Can do. As the component (q), one or more selected from silica gel, zeolite, activated carbon, and allophane are preferable, and among these, silica gel is most preferable.
[0034]
The specific surface area of component (q) is 100 m²/ G or more (preferably 200 m²/ G or more, more preferably 300 m²/ G or more). The specific surface area is a value measured by the BET method.
The mixing amount of the component (q) is 10 to 600 parts by weight with respect to 100 parts by weight of the solid content of the component (p). When the amount of component (q) is less than 10 parts by weight, sufficient adsorption / desorption performance and hysteresis characteristics cannot be obtained. If it exceeds 600 parts by weight, the undercoat layer tends to be brittle, and the risk of cracking increases.
[0035]
In addition to the above-described components, the primer composition preferably further contains (r) moisture-absorbing / releasing synthetic resin fine particles (hereinafter referred to as “(r) component”).
The component (r) has moisture absorption / release properties. Specifically, the moisture absorption rate at a temperature of 20 ° C. and a relative humidity of 45% is 10 wt% or more (preferably 20 wt% or more, more preferably 30 wt% or more). Certain hygroscopic synthetic resin fine particles can be suitably used.
The moisture absorption rate at a temperature of 20 ° C. and a relative humidity of 45% means that the sample was dried at 120 ° C. for 1 hour and then absorbed by a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 45% for 24 hours. It is a value obtained by measuring the change in weight, and can be determined by the following formula.
Moisture absorption rate (wt%) = {(weight after moisture absorption−weight after drying) / weight after drying} × 100
[0036]
Component (r) is, for example, one or more monomers such as various (meth) acrylic acid esters, acrylamides, aromatic vinyls, vinyl esters, vinyl halides, etc., by a known method. Although it is obtained by copolymerization, it is desirable to have a crosslinked structure from the viewpoint of improving water vapor adsorption and desorption. Such a crosslinked structure can be formed by a method such as introduction of a crosslinkable monomer in the polymerization stage, introduction of a crosslinkable compound after polymerization. As the crosslinkable monomer, divinylbenzene, ethylene glycol di (meth) acrylate, methylenebisacrylamide and the like can be suitably used, and as the crosslinkable compound, a hydrazine-based compound can be suitably used.
[0037]
The component (r) is preferably a reactive functional group-containing hygroscopic synthetic resin fine particle. As such a reactive functional group, those similar to the component (p-1) can be used. In the present invention, a carboxyl group is particularly preferably used. The method for introducing a carboxyl group into the component (r) is not particularly limited. For example, homopolymerization of a monomer having a carboxyl group or copolymerization with another copolymerizable monomer (meta) ) A method in which a polymer obtained by copolymerizing a cyano group-containing monomer such as acrylonitrile is subjected to a hydrolysis treatment, a method by oxidation of alkene, alkyl halide, alcohol, aldehyde, or the like. The carboxyl group content of the component (r) is desirably 1 mmol / g or more.
[0038]
The mixing amount of the component (r) is 2 to 100 parts by weight, preferably 10 to 40 parts by weight with respect to 100 parts by weight of the solid content of the component (p). If this amount is less than 2 parts by weight, the water vapor adsorptivity per unit time tends to decrease. If it exceeds 100 parts by weight, the undercoat layer tends to be brittle, and the risk of cracking increases.
The particle size of the component (r) is not particularly limited, but those having a size of about 0.1 to 100 μm can be used.
[0039]
In the primer composition, when the reactive functional group-containing synthetic resin binder is used as the component (p-1) and the reactive functional group-containing hygroscopic synthetic resin fine particles are used as the component (r), It is desirable to use a cross-linking agent (hereinafter referred to as “(s) component”) having a functional group capable of reacting with the reactive functional group of component p-1) and component (r). The component (s) preferably contains two or more of these functional groups in one molecule.
The functional group of the component (s) is not limited as long as it can react with the component (p-1) and the component (r), but in the present invention, a carbodiimide group that is a functional group capable of reacting with a carboxyl group in particular. , An epoxy group, an aziridine group, an oxazoline group, and the like are preferably used.
[0040]
Specific examples of the component (s) include, for example, those described in JP-A-10-60272, JP-A-10-316930, JP-A-11-60667, and the like as a crosslinking agent containing a carbodiimide group. As a crosslinking agent containing an epoxy group, polyethylene glycol diglycidyl ether, polyhydroxyalkane polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc., as a crosslinking agent containing an aziridine group, 2,2-bishydroxymethylbutano -Lutris [3- (1-aziridinyl) propionate], 1,6-hexamethylenediethyleneurea, diphenylmethane-bis-4,4'-N, N'-diethyleneurea and the like as a crosslinking agent containing an oxazoline group, 2-Vinyl-4-methyl-2-oxa Phosphorus, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-polymerizable oxazoline compound of oxazoline each compound and copolymerizable monomer copolymerized with resins.
[0041]
In the primer composition, in addition to the above-described components, it is desirable to further contain (t) a polyether-modified polysiloxane compound (hereinafter referred to as “(t) component”). Component (t) is a component that mainly improves wettability. When a primer composition is applied to the exterior surface of a building, dripping or repelling of the primer composition can be suppressed, resulting in excellent coating work. Therefore, it is possible to easily form a uniform and smooth undercoat layer. In addition, even when the topcoat composition is applied onto the undercoat layer formed by the undercoat composition, it is possible to suppress dripping or repellency of the topcoat composition and to impart excellent coating workability. A uniform and smooth overcoat layer can be easily formed. The component (t) is not particularly limited, and examples thereof include those shown in Chemical formula 1.
[0042]
[Chemical 1]

[0043]
R in the formula₁Is a methyl group, an ethyl group, R₂, R₃Is a methyl group, an ethyl group or R₄A group represented by R₄Is -R₅(CH₂CH₂O)_a(CH₂CH (CH₃O)_bR₆(R₅Is, for example, an alkylene group (preferably having 1 to 3 carbon atoms). R₆Is, for example, an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a cycloalkyl group having 6 to 12 carbon atoms such as a cyclohexyl group, a carbon number 2 such as a vinyl group or an allyl group. An alkenyl group having 8 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms such as a phenyl group and a tolyl group, an aralkyl group having 7 to 12 carbon atoms such as a benzyl group and a phenylethyl group, and at least a part of hydrogen atoms of these groups Are substituted with a halogen atom, a cyano group or the like, for example, a chloromethyl group, a trifluoropropyl group, a cyanoethyl group, or the like. a and b are each an integer of 0 to 20, and a + b ≧ 1. ), N and m are each an integer of 0 to 100, provided that when n = 0, R₂And / or R₃Is R₄And
[0044]
Component (t) is blended in an amount of 0.05 to 15 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the solid content of component (p). If the amount is less than 0.05 parts by weight, the wettability improvement effect is difficult to obtain and the coating workability may be inferior. If the amount exceeds 15 parts by weight, the adhesion to the exterior surface of the building or the topcoat layer may be adversely affected. is there.
[0045]
In the primer composition, in addition to the above-mentioned components, an alkoxysilane compound can also be contained. The alkoxysilane compound is localized on the surface of the coating during the formation of the undercoat layer coating, and can contribute to improving the adhesion with the overcoat layer. For example, the alkoxysilane compound is localized on the coating surface. From the viewpoint of easiness, etc., a condensate of an alkoxysilane having 1 to 2 carbon atoms and an alkoxysilane group having 3 or more carbon atoms, or a polyoxyalkylene having 1 to 4 carbon atoms in a repeating unit And a condensate of an alkoxysilane containing an alkoxyl group having 1 to 4 carbon atoms.
[0046]
In the primer composition, in addition to the above components, various additives such as pigments, aggregates, fibers, thickeners, leveling agents, plasticizers, antiseptics, antifungal agents, algaeproofing agents, antibacterial agents, A dispersant, an antifoaming agent, an ultraviolet absorber, an antioxidant and the like can also be included.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0048]
The present invention comprises a coating formed on the surface of a building exterior surface, and means for supplying water to the coating surface. The present invention is mainly applicable to building exterior surfaces such as roofs, rooftops, and outer walls. FIG. 1 shows an example in which the temperature suppression structure of the present invention is applied to a roof of a building as an example.
[0049]
In the present invention, as the means for supplying water, various means can be used as long as water can be supplied to the coating surface.
In FIG. 1, the apparatus etc. which pump up water with the pump 3 from the water supply source 2, and sprinkle from the nozzle 4 provided in the top part of the roof are provided.
Here, as the water supply source 2, a water tank, a well, a water pipe etc. can be used, for example. Considering reduction of environmental load, cost, etc., a water storage tank equipped with a rainwater collecting structure is suitable.
A water supply pipe 5 may be used to connect the water supply source 2, the pump 3, and the nozzle 4. Further, the water supply pipe 5 can be appropriately provided with a flow rate adjusting valve for adjusting the amount of water supplied.
The water flowing down from the roof can be reused by collecting it in a water storage tank or the like.
When water is supplied to the wall surface of the building, the nozzle 4 may be arranged on the upper surface of the wall surface. Other configurations can be the same as those shown in FIG.
[0050]
FIG. 2 is a view showing a laminated coating 7 provided on the substrate 6.
The substrate 6 is not particularly limited. For example, concrete, mortar, fiber-mixed cement board, cement calcium oxalate board, slag cement pearlite board, asbestos cement board, lightweight concrete board, siding board, extrusion molding board, galvanizing Steel plate, zinc-iron alloy plated steel plate, zinc-aluminum alloy plated steel plate, aluminum plated steel plate, chrome plated steel plate, nickel plated steel plate, zinc-nickel alloy plated steel plate, tin plated steel plate, stainless steel plate, aluminum plated stainless steel plate, lead plated stainless steel A steel plate, a galvanized stainless steel plate, etc. are mentioned.
[0051]
The undercoat layer 8 in the present invention has water vapor adsorption / desorption properties, and the water vapor adsorption / desorption properties exhibit hysteresis characteristics.
Here, the water vapor adsorption / desorption hysteresis characteristic is an adsorption / desorption isotherm when the relative humidity is on the horizontal axis and the water vapor adsorption / desorption amount is on the vertical axis, as shown in FIG. Means that it is on the upper side. This adsorption / desorption isotherm is obtained by sequentially raising the relative humidity from a low state to a high state with a constant temperature (set to 25 ° C.) and then returning it to a low state again. It represents the amount of water vapor that can be held per unit.
Specifically, it is first left in a thermo-hygrostat at a temperature of 25 ° C. and a relative humidity of 40% until the weight of the undercoat layer is balanced, and the weight after being left is measured. Next, the same operation is performed in a constant temperature and humidity chamber where only the humidity is increased at the same temperature, and measurement is performed up to a relative humidity of 90% while increasing only the humidity step by step. Thereafter, the same operation is repeated while gradually decreasing the humidity at the same temperature, and the weight is measured. By calculating the water vapor adsorption / desorption amount from the weight of the undercoat layer 8 at each humidity obtained by such measurement, an adsorption / desorption isotherm showing water vapor adsorption / desorption can be obtained.
[0052]
In the present invention, by having such a water vapor adsorption / desorption property, the primer layer 8 that adsorbs moisture in the atmosphere desorbs the moisture as the temperature rises, and at that time, the primer layer is formed by the latent heat of vaporization of water. Since heat is taken away from 8, the temperature rise can be suppressed. Furthermore, this hysteresis characteristic can adsorb moisture in the atmosphere at low temperatures, such as at night, and exert an effect of suppressing temperature rise due to desorption during the day when the temperature rises. While the undercoat layer 8 exhibits the temperature rise suppressing effect, it is not necessary to supply water to the coating surface.
[0053]
The undercoat layer 8 is formed of an undercoat material composition containing (p) a binder and (q) porous inorganic powder. The (q) component is a component that works effectively to impart hysteresis characteristics to the undercoat layer, and by containing the (q) component, the effect of suppressing the temperature rise due to the latent heat of vaporization of water can be maintained for a long time. It becomes possible. In the primer composition, it is desirable to contain (r) hygroscopic synthetic resin fine particles in addition to the components (p) and (q). By containing the component (r), the water vapor adsorption / desorption amount can be increased, and the water vapor adsorption / desorption rate can be increased. Furthermore, it becomes possible to improve the intensity | strength of the undercoat layer 8, and water vapor | steam adsorption / desorption property by including a crosslinking agent ((s) component) in undercoat material composition.
[0054]
On the outermost surface of the building exterior surface, an overcoat layer 9 having a contact angle with water of the coating surface of 70 ° or less is formed. Since such a topcoat layer 9 has high hydrophilicity and excellent water retention performance, when water is supplied to the surface of the topcoat layer 9, the water is applied to the surface of the topcoat layer even if the amount supplied is small. It spreads wet enough. And the temperature rise of a building can be suppressed by the vaporization latent heat at the time of water evaporating. In addition, the water can be uniformly supplied to the undercoat layer 8 by spreading the water over the entire topcoat layer 9 by supplying water.
The contact angle of the topcoat layer 9 with respect to water needs to be 70 ° or less, preferably 50 ° or less, and more preferably 30 ° or less.
[0055]
The topcoat layer 9 is a topcoat composition obtained by mixing (a) a tetraalkoxysilane compound, (b) a catalyst, (c) water, (d) a solvent, and (e) a quaternary cation base-containing polymer. Formed by things. Since the topcoat layer 9 formed by such a topcoat material composition has sufficient water vapor permeability, it does not inhibit the water vapor adsorption / desorption of the undercoat layer 8.
[0056]
When forming a film on the substrate 6, first, a primer composition is applied. The undercoat material composition may be applied directly to the substrate 6 or may be applied after some surface treatment (such as a base treatment with a sealer, a surfacer, a filler, or the like). It is also possible to apply to a substrate on which a film has already been formed. When applying the primer composition, for example, a spray, a roller, a brush, or the like can be used. When pre-coating at a factory or the like, a roll coater, a flow coater or the like can be used.
After the undercoat layer 8 is formed, the topcoat material composition is applied and laminated. In the top coating composition, it can be applied by a method such as a method of impregnating and wiping paper, cloth, nonwoven fabric or the like. In addition, it can also apply using a spray, a roller, a brush, a roll coater, a flow coater, etc.
The thickness of the formed layer is usually about 5 to 150 μm for the undercoat layer and about 0.01 to 10 μm for the top coat layer.
[0057]
The results of performance tests on the laminated coating 7 are shown below.
[0058]
FIG. 4 shows the water vapor adsorption / desorption properties of the undercoat layer formed of various undercoat material compositions.
The undercoat layers A to E are formed by applying the undercoat material compositions A to E on an aluminum plate so that the dry film thickness is 500 μm. In addition, undercoat material composition AE was manufactured by mixing each raw material according to the ratio shown in Table 2 using the raw material shown in Table 1.
[0059]
[Table 1]

[0060]
[Table 2]

[0061]
FIG. 5 shows the water vapor adsorption / desorption property of a film in which an overcoat layer is laminated on an undercoat layer. The laminated coatings A to E are formed by applying the top coating composition A to the undercoat layers A to E so that the dry film thickness is 0.5 μm.
In addition, as the top coating composition A, a partial hydrolysis condensate of tetramethoxysilane (average molecular weight 500, SiO₂51% by weight) SiO₂100 parts by weight in terms of conversion were prepared, 0.5 parts by weight of aluminum tris (acetylacetonate), 5400 parts by weight of ethanol, and 7500 parts by weight of water were mixed and stirred for about 30 minutes, and then further quaternary. Cation base-containing polymer (methyl acrylate-ethyl acrylate-polyglycerol diacrylate-dimethylaminoethyl methacrylate quaternized copolymer aqueous solution, ratio of dimethylaminoethyl methacrylate quaternized to 28% by weight of all monomers, solid 30 wt%) was obtained by uniformly mixing 13 parts by weight in terms of solid content. The contact angle to water of the coating formed by this topcoat composition A was measured with a CA-A type contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd.) (measurement temperature 23 ° C.) and found to be 25 °. It was.
[0062]
The laminated coating F is obtained by coating the undercoating layer A with the top coating composition B so that the dry film thickness is 0.5 μm.
In addition, as the overcoating material composition B, a partial hydrolysis-condensation product of tetramethoxysilane (average molecular weight 500, SiO₂51% by weight) SiO₂100 parts by weight in terms of conversion were prepared, 0.5 parts by weight of aluminum tris (acetylacetonate), 5400 parts by weight of ethanol, and 7500 parts by weight of water were mixed and stirred for about 30 minutes. Cation base-containing polymer (methyl acrylate-ethyl acrylate-polyglycerol diacrylate-dimethylaminoethyl methacrylate quaternized copolymer aqueous solution, ratio of dimethylaminoethyl methacrylate quaternized to 28% by weight of all monomers, solid Obtained by mixing 13 parts by weight in terms of solid content and further mixing 100 parts by weight in terms of solid content of silica sol (solid content 30% by weight, particle diameter 10 to 20 nm, dispersion medium: isopropyl alcohol). Used. The water contact angle of the coating formed by this topcoat composition B was measured with a CA-A type contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd.) (measurement temperature: 23 ° C.) and found to be 23 °. It was.
[0063]
The laminated coating G is formed by applying the top coating composition C to the undercoat layer A so that the dry film thickness is 30 μm. The top coating composition C used was a solvent-soluble acrylic resin (methyl methacrylate / butyl acrylate / vinyl acetate copolymer, nonvolatile content 50% by weight). The water contact angle of the coating formed by the top coating composition C was measured with a CA-A contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd.) (measurement temperature 23 ° C.), and found to be 83 °. It was.
[0064]
As is clear from FIGS. 4 and 5, the topcoat layer formed of the topcoat composition A containing the components (a) to (e) does not inhibit the water vapor adsorption / desorption property of the undercoat layer. Moreover, the topcoat layer formed of the topcoat composition B containing the components (a) to (f) also does not inhibit the water vapor adsorption / desorption property of the undercoat layer.
[0065]
FIG. 6 shows the results of a heat shielding test performed on the multilayer coatings A to G.
In this thermal insulation test, first, the specimen is left in a thermo-hygrostat with a temperature of 25 ° C. and a relative humidity of 90% until the weight of each specimen is balanced, and then an infrared lamp is laminated using a 250 W infrared lamp. The film surface was irradiated for 360 minutes, and the back surface temperature of the substrate was measured.
From FIG. 6, it was confirmed that the multilayer coatings A to D and the multilayer coating F exhibited an excellent temperature rise suppressing effect. The laminated coatings E and G had low water vapor adsorption / desorption properties, and the temperature increase in the heat shielding test was remarkable.
[0066]
7 and 8 are views showing the state of wetting of the coating surface when water is supplied to the laminated coating. As for the laminated coating A and the laminated coating F, as shown in FIG. 7, the supplied water broadly spreads and a uniform water film is formed. On the other hand, in the multilayer coating G, the water supplied from the nozzles flowed down in a streak shape as shown in FIG.
In order to confirm the effect of suppressing the temperature rise of each laminated coating at the time of water supply, after irradiating each laminated coating in a dry state with an infrared lamp for 30 minutes, a certain amount of water is supplied from the nozzle, and the substrate at this time The back surface temperature change of was measured. As a result, in the multilayer coating A, the temperature could be lowered by 18 ° C. by supplying water. In the laminated film F, the temperature could be lowered by 20 ° C. On the other hand, in the laminated film G, it was only lowered by 10 ° C.
[0067]
On the other hand, an undercoat material composition H was produced by adding 0.25 parts by weight of a polyether-modified polysiloxane compound to the above-described undercoat material composition A. The undercoat material composition H is applied and formed on an aluminum plate so that the dry film thickness is 50 μm, and then the overcoat material composition A is applied and formed so that the dry film thickness is 0.5 μm. H was obtained. At this time, in the application of the undercoat material composition H and the overcoat material composition A, no sagging or repellency was observed, and a uniform and smooth coating film could be easily formed. With respect to the multilayer coating H, results equivalent to those of the multilayer coating A were obtained in the water vapor desorption test and the heat shielding test.
[0068]
【The invention's effect】
In this invention, the specific undercoat layer is provided in the film of the building exterior surface. This undercoat layer can autonomously adsorb moisture in the atmosphere, and can suppress an increase in the temperature of the building due to latent heat of vaporization when the moisture vaporizes. For this reason, it is not necessary to supply water while the undercoat layer exhibits the effect of suppressing the temperature rise due to the desorption of moisture.
On the other hand, a specific topcoat layer with high hydrophilicity is provided on the outermost surface of the coating, so that when water is supplied, even if the amount of water is small, it spreads widely and efficiently cools. It can be performed.
Further, water can be uniformly supplied to the undercoat layer by supplying water on the surface of the coating. By this water replenishment, the cooling effect by the undercoat layer is exhibited again.
In the present invention, due to the interaction between the undercoat layer and the overcoat layer, the temperature rise inside the building can be efficiently suppressed, and the cooling use in summer can be reduced. Moreover, the heat island phenomenon which has been a problem in recent years can also be suppressed.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an embodiment of the present invention.
FIG. 2 is a view showing a cross section of the laminated coating of the present invention.
FIG. 3 is a graph showing hysteresis characteristics
FIG. 4 is a graph showing water vapor adsorption / desorption properties (undercoat layers A to E).
FIG. 5 is a graph showing water vapor adsorption / desorption properties (laminated coatings A to G).
FIG. 6 is a graph showing a heat shielding test (laminated coatings A to G).
FIG. 7 is a diagram showing the situation when water is supplied (laminated coatings A and F).
FIG. 8 is a diagram showing the situation when water is supplied (laminated coating G).
[Explanation of symbols]
1: Building
2: Water supply source
3: Pump
4: Nozzle
5: Water supply pipe
6: Base material
7: Laminated coating
8: Undercoat layer
9: Topcoat layer
10: Water

Claims (5)

A temperature rise suppressing structure for a building comprising a coating formed on the surface of a building exterior surface, and means for supplying water to the coating surface, the coating comprising:
(P) an undercoat layer formed of an undercoat material composition obtained by mixing a binder, (q) a porous inorganic powder, and (t) a polyether-modified polysiloxane compound, and having a water vapor adsorption / desorption property having hysteresis characteristics And (a) a tetraalkoxysilane compound, (b) a catalyst, (c) water, (d) a solvent, and (e) a quaternary cation base-containing polymer. A structure for suppressing temperature rise of a building, comprising an overcoat layer having a contact angle with water on the surface of the coating of 70 ° or less. Undercoat layer
(P) 100 parts by weight of binder in solids,
(Q) 10 to 600 parts by weight of porous inorganic powder,
The temperature rise of the building according to claim 1, characterized in that it is formed of a primer composition containing (t) 0.05 to 15 parts by weight of a polyether-modified polysiloxane compound. Suppression structure. The structure for suppressing temperature increase of a building according to claim 2, wherein the undercoat material composition further contains (r) 2 to 100 parts by weight of hygroscopic synthetic resin fine particles. In the primer composition, (p) contains a reactive functional group-containing synthetic resin binder, (r) is a reactive functional group-containing hygroscopic synthetic resin fine particle,
(S) Containing a cross-linking agent having a functional group capable of reacting with the functional group, The structure for suppressing temperature increase of a building according to claim 2 or claim 3. In addition to the components (a) to (e), the top coat layer is further formed of a top coat composition obtained by further mixing (f) a metal oxide sol having a particle size of 3 to 100 nm. The temperature rise suppressing structure for a building according to any one of claims 1 to 4.

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