以下，基於本發明之較佳之實施形態對本發明進行說明。本發明之樹脂組合物係用於製造印刷佈線板者。即，本發明係關於印刷佈線板用樹脂組合物。本發明之樹脂組合物含有馬來醯亞胺化合物、(甲基)丙烯酸系樹脂、硬化促進劑、及無機填料作為其構成成分。以下，分別對該等成分進行詳細說明。 馬來醯亞胺化合物係具有至少1個馬來醯亞胺部位之化合物。就提高樹脂組合物之低翹曲化且使耐熱性提昇之觀點而言，尤佳為使用馬來醯亞胺部位為2個之馬來醯亞胺化合物(所謂之雙馬來醯亞胺化合物)或馬來醯亞胺部位為3個以上之聚馬來醯亞胺化合物。 作為構成馬來醯亞胺化合物之分子骨架，例如，可列舉聯苯骨架、4,4'-二苯甲烷骨架、苯甲烷骨架、伸苯基骨架及二苯醚骨架以及該等之組合。該等之中，就保持充分之耐熱性並且進一步提高樹脂組合物之可撓性且進一步提高流動性之觀點而言，較佳為使用具有聯苯骨架、4,4'-二苯甲烷骨架或苯甲烷骨架之馬來醯亞胺化合物。該等馬來醯亞胺化合物可單獨使用1種或將2種以上組合而使用。該等之中，就耐熱性及B-階段之龜裂耐受性更高之方面而言，最佳為包括聯苯骨架之馬來醯亞胺化合物。 馬來醯亞胺化合物之馬來醯亞胺當量較佳為100～1000，更佳為150～800，進而較佳為200～400。藉由將馬來醯亞胺當量設定於該範圍內，而可保持充分之耐熱性，並且樹脂組合物之可撓性進一步提高，且流動性進一步提高。 於本發明之樹脂組合物中，相對於馬來醯亞胺化合物、(甲基)丙烯酸系樹脂、及硬化促進劑之合計100質量份，較佳為包含25質量份以上且93質量份以下之馬來醯亞胺化合物，進而較佳為包含28質量份以上且70質量份以下之馬來醯亞胺化合物，進一步較佳為包含30質量份以上且50質量份以下之馬來醯亞胺化合物。藉由將馬來醯亞胺化合物之調配量設定於該範圍內，而樹脂組合物之可撓性進一步提高，且流動性進一步提高。 本發明之樹脂組合物所包含之(甲基)丙烯酸系樹脂主要係為了提高樹脂組合物之可撓性而調配。又，亦為了藉由與上述馬來醯亞胺化合物併用以提高樹脂組合物之可撓性而調配。所謂(甲基)丙烯酸系樹脂係丙烯酸系樹脂及甲基丙烯酸樹脂之統稱。(甲基)丙烯酸系樹脂係將丙烯酸或其衍生物作為聚合性單體之一聚合而成之樹脂、或將甲基丙烯酸或其衍生物作為聚合性單體之一聚合而成之樹脂、或將丙烯酸或其衍生物及甲基丙烯酸或其衍生物作為聚合性單體聚合而成之樹脂。作為丙烯酸及甲基丙烯酸衍生物，可列舉該等酸之酯或其環氧改性物、羥基改性物、羧基改性物、胺基改性物、醯胺基改性物等。 於(甲基)丙烯酸系樹脂為包含2種以上之重複單元之共聚物之情形時，該共聚物中之重複單元之配置可為無規，亦可為嵌段，亦可為接枝。於共聚物中包含(甲基)丙烯酸或其衍生物以外之重複單元作為共聚合成分之情形時，作為該重複單元，例如，可列舉源自丙烯腈之重複單元或源自丁二烯之重複單元、及源自苯乙烯之重複單元等。 (甲基)丙烯酸系樹脂亦可於高分子鏈之末端、側鏈或主鏈具有各種官能基。作為此種官能基，例如，可列舉與環氧樹脂及硬化劑之至少一者具有反應性之基。具體而言，例如，可列舉環氧基、羥基、羧基、胺基及醯胺基等。藉由該等官能基包含於(甲基)丙烯酸系樹脂中，而能夠與例如樹脂組合物中所包含之其他成分反應，藉此，可期待實現樹脂組合物之耐熱性、對熱之尺寸穩定性、及吸濕耐受性(焊料耐熱性)等之提昇。上述各種官能基之中，特佳為環氧基。亦可於(甲基)丙烯酸系樹脂每1個分子中包含複數個官能基。 (甲基)丙烯酸系樹脂之重量平均分子量(以下亦稱為「MW」)較佳為5萬以上，進而較佳為7萬以上，進一步較佳為10萬以上。關於重量平均分子量之上限值，較佳為100萬以下，進而較佳為90萬以下，進一步較佳為70萬以下。藉由使用具有該範圍之分子量之(甲基)丙烯酸系樹脂，而對本發明之樹脂組合物賦予充分之可撓性，即便於形成B-階段狀態之樹脂片之情形時，亦能夠防止龜裂等之產生。(甲基)丙烯酸系樹脂之重量平均分子量例如可藉由JIS K7252-1：2008所規定之尺寸排除層析法(SEC，Size Exclusion Chromatography)或凝膠滲透層析法分析(GPC，Gel Permeation Chromatograph)進行測定。 於本發明之樹脂組合物中，相對於馬來醯亞胺化合物、(甲基)丙烯酸系樹脂、及硬化促進劑之合計100質量份，較佳為包含7質量份以上且70質量份以下之(甲基)丙烯酸系樹脂，進而較佳為包含10質量份以上且60質量份以下之(甲基)丙烯酸系樹脂，進一步較佳為包含15質量份以上且50質量份以下之(甲基)丙烯酸系樹脂。藉由將(甲基)丙烯酸系樹脂之調配量設定於該範圍內，而樹脂組合物之可撓性及流動性進一步提高且耐熱性亦優異。 本發明之樹脂組合物所包含之硬化促進劑係用於促進該樹脂組合物中所包含之馬來醯亞胺化合物之硬化。硬化促進劑尤佳為亦促進作為聚合性反應性基之1種之環氧基之聚合反應(交聯反應)之化合物。作為此種硬化促進劑，例如，可列舉胺系化合物及磷化合物等。該等硬化促進劑可單獨使用1種或將2種以上組合而使用。其中，就兼顧保存穩定性及硬化反應促進之觀點而言，硬化促進劑較佳為於雜環中包含氮原子之雜環式芳香族胺。 該等之中，就硬化物之耐熱性及絕緣可靠性之觀點而言，硬化促進劑特佳為咪唑系化合物。作為咪唑系化合物之例，可列舉2-甲基咪唑、2-乙基-4-甲基咪唑、2-苯基咪唑、2-苯基-4-甲基咪唑、1-苄基-2-甲基咪唑、1-苄基-2-苯基咪唑、1,2-二甲基咪唑等。 於本發明之樹脂組合物中，相對於馬來醯亞胺化合物、(甲基)丙烯酸系樹脂及硬化促進劑之合計100質量份，較佳為包含0.01質量份以上且10質量份以下之硬化促進劑，進而較佳為包含0.10質量份以上且5質量份以下之硬化促進劑，進一步較佳為包含0.15質量份以上且3質量份以下之硬化促進劑。藉由將硬化促進劑之調配量設定於該範圍內，而能夠使樹脂組合物充分地硬化。 本發明之樹脂組合物除上述各成分以外，包含無機填料。無機填料係為了對由本發明之樹脂組合物產生之硬化體賦予對熱之尺寸穩定性而調配。或者，為了對本發明之樹脂組合物賦予適度之流動性或可撓性而調配。進而，為了防止本發明之樹脂組合物產生黏連而調配者。無機填料之種類並無特別限制，例如，可列舉二氧化矽、硫酸鋇、燒成滑石、鉬酸鋅處理滑石、鈦酸鋇、氧化鈦、黏土、氧化鋁、雲母、軟水鋁石、硼酸鋅、錫酸鋅、氫氧化鋁、碳酸鈣、氫氧化鎂、矽酸鎂、玻璃短纖維、硼酸鋁晶鬚及碳酸矽晶鬚等。該等無機填料可單獨使用1種，或者亦可將2種以上組合而使用。 該等之中，就對由樹脂組合物產生之硬化體賦予對熱之尺寸穩定性，並且賦予容易獲取性、硬化體之耐熱性及絕緣可靠性等之觀點而言，無機填料較佳為二氧化矽。作為二氧化矽，已知有無定形二氧化矽、熔融二氧化矽、結晶二氧化矽、合成二氧化矽、中空二氧化矽等二氧化矽，就可高填充地添加至樹脂組合物中且B-階段狀態之樹脂片之施加熱時之流動性(樹脂溢流量)之良好性之觀點而言，特佳為球狀者。 無機填料之形狀或大小並無特別限制。關於形狀，例如，可採用球狀、多面體狀、針狀、紡錘狀、不定形等。亦可使用該等形狀之2種以上之組合。關於大小，平均粒徑較佳為0.001 μm以上且20 μm以下，進而較佳為0.01 μm以上且10 μm以下，進一步較佳為0.05 μm以上且5 μm以下。亦可將平均粒徑不同之2種以上之無機填料組合而使用，於粒度分佈中觀察到複數個峰。平均粒徑係根據由使用雷射繞射、散射式之粒徑分佈測定裝置之粒度分佈曲線求出之中徑(D50
)而測定。粒子之長徑與短徑之比即縱橫比並無特別限制。但是，當製造本發明之製品時，就樹脂溢流量或賦予可撓性時之控制之容易性之觀點而言，縱橫比較佳為1.0以上且10以下，更佳為1.0以上且5.0以下，最佳為1.0以上且2.0以下。 就使樹脂成分與無機填料之密接性提昇之方面，以及使樹脂組合物之吸濕耐受性提昇之方面等而言，無機填料之表面較佳為被實施利用矽烷偶合劑進行之表面處理。作為矽烷偶合劑，例如，可列舉胺基官能性矽烷偶合劑、丙烯醯基官能性矽烷偶合劑、甲基丙烯基官能性矽烷偶合劑、環氧基官能性矽烷偶合劑、烯烴官能性矽烷偶合劑、巰基官能性矽烷偶合劑、及乙烯基官能性矽烷偶合劑等。該等之中，更佳為環氧基官能性矽烷偶合劑、胺基官能性矽烷偶合劑、丙烯醯基官能性矽烷偶合劑、甲基丙烯基官能性矽烷偶合劑、及乙烯基官能性矽烷偶合劑等。 於本發明之樹脂組合物中，相對於馬來醯亞胺化合物、(甲基)丙烯酸系樹脂及硬化促進劑之合計100質量份，較佳為包含100質量份以上且400質量份以下之無機填料，進而較佳為包含100質量份以上且350質量份以下之無機填料，進一步較佳為包含150質量份以上且300質量份以下之無機填料。藉由將無機填料之調配量設定於該範圍內，而對B-階段狀態之樹脂片施加熱時之流動性(樹脂溢流量)變得良好，又，可獲得對熱之硬化體之尺寸穩定性及耐熱性良好之特性。 本發明之樹脂組合物除以上所說明之成分以外，亦可視需要包含其他成分。作為其他成分，例如，可列舉環氧樹脂、阻燃劑、阻燃助劑、偶合劑、密接賦予劑、著色劑、雷射加工性提昇劑、抗氧化劑、抗紫外線劣化劑、脫模劑、PH值調整劑、離子捕捉劑、消泡劑、調平劑、抗黏連劑、增黏劑、觸變性賦予劑及上述樹脂以外之其他樹脂等。尤其是若本發明之樹脂組合物包含環氧樹脂，則硬化體之耐熱性提昇，對熱之尺寸穩定性進一步提昇，進而，吸濕耐受性亦進一步提昇，就此方面而言有利。 作為環氧樹脂，可無特別限制地使用於該技術領域中以往所使用者。例如，可列舉萘型環氧樹脂、聯苯芳烷基型環氧樹脂、甲酚酚醛清漆型環氧樹脂、雙酚A型環氧樹脂、雙酚F型環氧樹脂、雙酚S型環氧樹脂、脂環式環氧樹脂、脂肪族鏈狀環氧樹脂、甲酚酚醛清漆型環氧樹脂、酚系酚醛清漆型環氧樹脂、烷酚酚醛清漆型環氧樹脂、芳烷基型環氧樹脂、聯苯酚型環氧樹脂、二環戊二烯型環氧樹脂、三羥基苯甲烷型環氧化合物、酚類與具有酚性羥基之芳香族醛之縮合物之環氧化物、雙酚之二縮水甘油醚化物、萘二醇之二縮水甘油醚化物、酚類之縮水甘油醚化物、醇類之二縮水甘油醚化物、異氰尿酸三縮水甘油酯等。該等環氧樹脂可單獨使用1種或將2種以上組合而使用。 上述環氧樹脂尤佳為萘型環氧樹脂及/或聯苯芳烷基型環氧樹脂。藉由使用該等環氧樹脂，硬化體之耐熱性進一步提昇，對熱之尺寸穩定性更進一步提昇，進而，吸濕耐受性亦更進一步提昇。就使該效果更加顯著之觀點而言，較佳為使用萘型環氧樹脂作為環氧樹脂。 以萘型環氧樹脂或聯苯芳烷基型環氧樹脂為首之上述環氧樹脂於本發明之樹脂組合物中，相對於馬來醯亞胺化合物、(甲基)丙烯酸系樹脂、硬化促進劑、及該環氧樹脂之合計100質量份，較佳為包含10質量份以上且40質量份以下，進而較佳為包含10質量份以上且30質量份以下，進一步較佳為包含15質量份以上且25質量份以下。 就使上述環氧樹脂之交聯反應更加緻密、使硬化體之耐熱性提昇之方面而言，更佳為使樹脂組合物中含有與環氧基具有反應性之硬化劑。作為此種硬化劑，例如，可列舉一級胺或二級胺等二胺系硬化劑、2官能以上之酚化合物、酸酐系硬化劑、雙氰胺等。該等硬化劑可單獨使用1種或將2種以上組合而使用。該等硬化劑有時作為以上所述之馬來醯亞胺化合物之硬化促進劑而發揮作用。於此種之情形時，該硬化劑係定位為硬化促進劑。 該等之中，就容易控制本發明之樹脂組合物之整體之熱硬化反應速度之方面而言，更佳為酚化合物、酸酐系硬化劑單獨或其等之組合所形成之硬化劑。其原因在於：該等化合物係僅有助於與環氧樹脂之硬化反應而無助於馬來醯亞胺化合物之硬化反應之化合物，因此，可防止整體之熱硬化反應速度急遽進行。其結果，可防止所獲得之絕緣層中之馬來醯亞胺硬化物或環氧樹脂硬化物之異常凝聚，因此，可保持系統內部均一性。 本發明之樹脂組合物可藉由將上述各成分在有機溶劑中混合並進行攪拌而獲得。作為有機溶劑，可使用與先前用於該種樹脂組合物之製備之溶劑相同者。作為此種有機溶劑之例，例如，可列舉甲醇、乙醇、甲基乙酮、甲苯、丙二醇單甲醚、二甲基甲醯胺、二甲基乙醯胺、環己酮、環戊酮、乙基溶纖劑、1,3-二氧戊環等。 如上所述，以此方式獲得之樹脂組合物係用於印刷佈線板之製造。例如，藉由使本發明之樹脂組合物成形為片狀，並加熱乾燥至B-階段之半硬化狀態，而可製成包含該樹脂組合物之印刷佈線板用樹脂片。藉由積層該樹脂片，而可製造印刷佈線板。 作為利用本發明之樹脂組合物製造印刷佈線板之一例，可將使樹脂片硬化而獲得之樹脂層單獨製成絕緣層。於將樹脂層單獨製成絕緣層之情形時，樹脂層之厚度較佳為0.5 μm以上且200 μm以下之範圍內，進而較佳為0.5 μm以上且150 μm以下之範圍內。藉由使樹脂層之厚度為該範圍，而能夠確保絕緣性所需之充分之厚度，能夠對B-階段之樹脂片賦予較高之可撓性。 或者，藉由使本發明之樹脂組合物浸漬於織布等纖維基材(布)中，並將由此獲得之浸漬體加熱乾燥至B-階段之半硬化狀態，而可製成包含該樹脂組合物之印刷佈線板用預浸體。藉由積層該預浸體，而可製造印刷佈線板。 作為上述纖維基材，並無特別限定，但可使用如平紋編織等般以經紗及緯紗大致正交之方式織成之基材。例如，可使用例如玻璃布等之無機纖維之織布。或者，可使用例如芳香族聚醯胺布、聚酯布等之有機纖維之織布。纖維基材之厚度並無特別限制，例如，較佳為10 μm以上且200 μm以下。 本發明之樹脂組合物除用作上述片或預浸體以外，亦可用作附帶支持體之印刷佈線板用樹脂片。該樹脂片較佳為具有支持體、及配置於該支持體之一面之本發明之樹脂組合物之層者。作為支持體，可使用各種膜狀或箔狀者。例如，可使用樹脂製膜作為支持體。或者亦可使用金屬箔作為支持體。就容易操作之方面而言，支持體之厚度較佳為5.0 μm以上且100 μm以下。 作為上述樹脂製膜，例如，可列舉聚對苯二甲酸乙二酯(PET)膜、聚萘二甲酸乙二酯(PEN)膜、芳香族聚醯胺膜、聚醯亞胺膜、尼龍膜、液晶聚合物等樹脂膜等。亦可使用於該等樹脂膜上具備金屬層塗層之金屬塗佈樹脂膜。作為金屬箔，例如，可列舉銅箔、鋁箔、不鏽鋼箔、鎳箔、鈦箔或其等中之任一者積層複數層而成之箔等。尤其是，於採用MSAP(Modified Semi-Additive Process，改性半加成)法、SAP(Semi-Additive Process，半加成)法或減成法等作為形成印刷佈線板時之佈線圖案加工法之情形時，就確保使樹脂組合物硬化而成之層與佈線之密接性之方面，以及兼顧金屬箔之蝕刻加工性之方面而言，支持體尤佳為金屬箔，更佳為銅箔。 於作為支持體之金屬箔之厚度未達例如5.0 μm之情形時，為了使附帶樹脂層之金屬箔之操作性提昇，尤其是為了使製造作為附帶樹脂層之金屬箔之印刷佈線板時之操作性提昇，支持體亦可於金屬箔之另一面設置所謂之剝離層及載體，而以附帶載體之金屬箔之形態使用。作為載體之例，除銅箔、鎳箔、不鏽鋼箔、鋁箔等金屬箔以外，可列舉PET膜、PEN膜、芳香族聚醯胺膜、聚醯亞胺膜、尼龍膜、液晶聚合物等樹脂膜、於樹脂膜上具備金屬層塗層之金屬塗佈樹脂膜等，典型而言為銅箔。剝離層可列舉有機剝離層及無機剝離層等。作為用於有機剝離層之有機成分之例，可列舉含氮有機化合物、含硫有機化合物、羧酸等。另一方面，作為用於無機剝離層之無機成分之例，可列舉Ni、Mo、Co、Cr、Fe、Ti、W、P、Zn、鉻酸鹽處理膜等。 關於上述金屬箔之與樹脂組合物層之接著面，基於JIS B0610-1994之表面粗糙度(Rzjis)較佳為4.0 μm以下，更佳為3.5 μm以下，進而較佳為3.0 μm以下。藉由使表面粗糙度(Rzjis)為該範圍，而能夠使對金屬箔進行蝕刻之後之樹脂層表面之凹凸微細，因此，能夠使形成於樹脂層之表面之上部導體層之尺寸精度較高。又，就保持上部導體層與樹脂層之密接性之觀點而言，金屬箔之表面粗糙度(Rzjis)較佳為0.005 μm以上，更佳為0.01 μm以上，進而較佳為0.05 μm以上。 進而，亦可於金屬箔之表面形成利用防銹覆膜處理等而成之表面處理層。作為防銹覆膜，可列舉使用鋅、鎳及鈷等之無機防銹覆膜、使用鉻酸鹽之鉻酸鹽覆膜、以及使用苯并***及咪唑等有機劑之有機防銹覆膜等。 又，亦可於上述表面處理層之表面形成矽烷層。藉由設置矽烷層，而使金屬箔之表面與樹脂層之密接性更良好。作為構成矽烷層之材料，例如，可列舉四烷氧基矽烷或矽烷偶合劑等。 無論支持體為何類材質，上述印刷佈線板用積層體均可藉由例如將由本發明之樹脂組合物獲得之B-階段之狀態之片狀物與支持體重疊並將其等一體地加熱加壓而獲得。加熱加壓可採用真空加壓法或真空層壓法。或者，可藉由在支持體之至少一面上塗敷本發明之樹脂組合物並將所獲得之塗膜加熱乾燥至B-階段之半硬化狀態而獲得。 該等附帶支持體之印刷佈線板用樹脂片除能夠以上述方式使樹脂片層硬化而用作絕緣層以外，亦能夠用作用以使預浸體與支持體(例如，金屬箔)之密接性提昇之底塗樹脂層。於用作底塗樹脂層之情形時，附帶支持體之印刷佈線板用樹脂片厚度較佳為0.4 μm以上且15 μm以下，更佳為0.5 μm以上且10 μm以下。藉由設為該範圍，而能夠確保用於充分提昇層間密接性之厚度，並且可設為於印刷佈線板之通孔加工(例如，雷射加工等)中適於微細加工之厚度。 於支持體與樹脂組合物之層之間，亦可視需要形成包括其他樹脂組合物之底塗層以提高兩者之接合強度。以此方式獲得之積層體之厚度較佳為例如10 μm以上且150 μm以下。 以此方式獲得之印刷佈線板用樹脂片或預浸體或積層體係使用本發明之樹脂組合物而形成，因此，對熱之尺寸穩定性較高，且抑制了施加外力時龜裂之產生。因此，該等印刷佈線板用樹脂片或預浸體或積層體尤其適合作為用以製造高性能之印刷佈線板之原料。作為印刷佈線板之加工方法，例如，可較佳地使用MSAP法或SAP法、減成法等。而且，使用該等印刷佈線板用樹脂片或預浸體或積層體所製造之印刷佈線板之對熱之尺寸穩定性較高，高頻特性良好。 實施例 以下，藉由實施例進一步詳細地說明本發明。然而，本發明之範圍並不限制於該實施例。若無特別說明，則「%」係指「質量%」。 以下之實施例及比較例中所使用之各成分如以下之表1所示。又，以下之表2至表4中之各成分之調配量係以質量份表示。 [表1]
[實施例1] 將以下之表2所示之成分，以該表所示之調配比，將溶劑設為甲基乙酮，以固形物成分成為60質量份之方式進行稱量，放入至燒瓶中，使其升溫至溫度60℃，利用螺旋漿式攪拌裝置攪拌1小時，而獲得樹脂組合物(樹脂清漆)。使用邊緣塗佈機(edge coater)，於附帶載體之銅箔之粗化處理面，以乾燥後之厚度成為100 μm之方式塗佈該樹脂組合物，以120℃、6分鐘之加熱條件使其乾燥，使溶劑揮發，而獲得積層有B-階段之半硬化狀態之樹脂之附帶樹脂層之銅箔。附帶載體之銅箔之表面粗糙度(Rzjis)為1.7 μm，厚度為2 μm。該附帶載體之銅箔被實施有鎳21 mg/m2
、鋅8 mg/m2
及鉻3 mg/m2
之防銹處理，且被實施有胺基系矽烷偶合劑之表面處理。 [實施例2] 於實施例1中，以乾燥後之厚度成為40 μm之方式形成樹脂層。除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。 [實施例3至14] 將樹脂組合物之調配設為如表2及表3所示，除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。 [比較例1] 於本比較例中，如表4所示，使用重量平均分子量較低者作為(甲基)丙烯酸系樹脂。除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。 [比較例2] 於本比較例中，不使用馬來醯亞胺化合物。又，使樹脂組合物之調配如表4所示。除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。 [比較例3] 於本比較例中，不使用(甲基)丙烯酸系樹脂。又，使樹脂組合物之調配如表4所示。除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。 [比較例4] 於本比較例中，不使用(甲基)丙烯酸系樹脂，而代替其使用聚乙烯醇縮醛樹脂。除此以外，以與實施例1相同之方式，獲得附帶樹脂層之銅箔。聚乙烯醇縮醛樹脂係於該技術領域中用作塑化劑之物質。 [評價] 針對實施例及比較例中所獲得之附帶樹脂層之銅箔，按照以下之方法對捲取時之龜裂防止性、抗黏連性及樹脂溢流量進行評價。 又，按以下之方法對使實施例及比較例中所獲得之附帶樹脂層之銅箔硬化之後之尺寸穩定性、玻璃轉移點、吸水率及介電特性(Df)進行測定。將其等之結果示於以下之表2至4。 [龜裂防止性] 將附帶樹脂層之銅箔切成10 cm×10 cm之尺寸，而獲得試樣片。將該試樣片以樹脂層側成為下表面側之方式載置於桌面上，將直徑10 mm之圓柱以其外周面接觸於銅箔表面之方式配置於上表面之銅箔表面之中央部，沿該圓柱將試樣片朝向上方彎折。此時，對樹脂層產生破裂(龜裂)之最低彎折角度進行測定。根據該角度，按以下之基準進行評價。AA：於135度以上無破裂(最佳)A：於90度以上且未達135度產生破裂(良好)B：於45度以上且未達90度產生破裂(正常)C：於未達45度產生破裂(不良) [抗黏連性] 將相同大小之附帶樹脂層之銅箔以其樹脂層面接觸於切成10 cm×10 cm之20 μm厚之附帶載體之銅箔之光澤面之方式重疊，施加500 g之負載，於溫度30℃、濕度40%RH之恆溫恆濕烘箱中保存48小時。其後取出，按以下之基準對樹脂層面與銅箔光澤面之附著之程度進行評價。A：無附著(良好)B：幾乎無附著(正常)C：有附著(不良) [樹脂溢流量] 所謂樹脂溢流量係以如下方式計算出之值，即，依據MIL標準中之MIL-P-13949G，自將樹脂層之厚度設為40 μm之附帶樹脂層之銅箔取樣4片10 cm見方之試樣，將該4片試樣以重疊之狀態(積層體)於加壓溫度171℃、加壓壓力1.4 MPa、加壓時間10分鐘之條件下貼合，測定此時之樹脂之流出質量，根據該測定結果並基於以下之式算出之值。根據該值，按以下之基準進行評價。樹脂溢流量(%)＝流出樹脂質量/(附帶樹脂層之銅箔質量﹣銅箔質量)×100A：8%以上且未達23%(良好)B：5%以上且未達8%、或23%以上且未達40%(正常)C：未達5%或40%以上(不良) [尺寸穩定性] 使2片附帶樹脂層之銅箔以使樹脂層彼此相對之方式貼合，利用真空加壓機加壓。加壓條件係設為220℃×90分鐘、1 MPa。進而，藉由蝕刻自加壓後之樣品去除銅箔。藉此，製作厚度約190 μm之樹脂膜。 但是，實施例2係藉由以下之方法製作樹脂膜。 使2片附帶樹脂層之銅箔以使樹脂層彼此相對之方式貼合，利用真空加壓機加壓。加壓條件係設為120℃×30秒、0.7 MPa。進而，使用烘箱於200℃×120分鐘之條件下使加壓後之樣品後硬化。藉由蝕刻去除已進行後硬化之樣品之銅箔。藉此，製作厚度約200 μm之樹脂膜。 針對以上之樹脂膜，對依據JIS C 6481而測得之熱膨脹係數進行測定，並設為尺寸穩定性之標準。根據其值，按以下之基準進行評價。A：未達20 ppm/℃(良好)B：20 ppm/℃以上且未達45 ppm/℃(正常)C：45 ppm/℃以上(不良) [玻璃轉移點] 使用尺寸穩定性之項中所獲得之樹脂膜，將其切成40 mm×5 mm。將其作為測定試樣，使用動態黏彈性測定裝置(DMA)對玻璃轉移點進行測定(測定條件：拉伸模式、頻率1 Hz、升溫速度：5℃/min)。根據其值，按以下之基準進行評價。A：260℃以上(良好)B：200℃以上且未達260℃(正常)C：未達200℃(不良) [吸水率] 基於JIS C6481進行測定。使用尺寸穩定性之項中所獲得之樹脂膜，將其切成50 mm×50 mm並測定質量。使測定試樣浸漬於已煮沸之水中1小時。其後，自水中提拉出，擦去附著於測定試樣之表面之水之後，對其質量進行測定，由浸漬前後之差計算出吸水量。根據其值，按以下之基準進行評價。A：未達0.7%(良好)B：0.7%以上且未達1.2%(正常)C：1.2%以上(不良) [介電特性] 使用上述[尺寸穩定性]之項中所獲得之樹脂膜，使用網路分析儀(Keysight公司製造，PNA-I N5234A)，藉由SPDR介電體共振器法，對3 GHz下之介電損耗正切進行測定。該測定係依據ASTMD2520(JIS C2565)而進行，將測定結果作為介電損耗正切(Df)之值。 [表2]
[表3]
[表4]
由表2或4所示之結果可明確，使用各實施例中所獲得之樹脂組合物而獲得之附帶樹脂層之銅箔均可防止龜裂之產生，且亦可防止黏連之產生。進而，樹脂組合物之流動性良好。而且，硬化體之尺寸穩定性優異，高頻下之介電特性(Df)亦較低。 [產業上之可利用性] 根據本發明，提供一種於B-階段之狀態下具有較高之可撓性且硬化體對熱之尺寸穩定性較高之印刷佈線板用樹脂組合物。Hereinafter, the present invention will be described based on a preferred embodiment of the present invention. The resin composition of the present invention is used for manufacturing a printed wiring board. That is, this invention relates to the resin composition for printed wiring boards. The resin composition of the present invention contains a maleimide compound, a (meth) acrylic resin, a hardening accelerator, and an inorganic filler as constituent components. Hereinafter, each of these components will be described in detail. The maleimide compound is a compound having at least one maleimide site. From the viewpoint of improving the low warpage of the resin composition and improving the heat resistance, it is particularly preferable to use a maleimide compound having two maleimide sites (a so-called bismaleimide compound). ) Or a maleimide compound having three or more maleimide sites. Examples of the molecular skeleton constituting the maleimide compound include a biphenyl skeleton, a 4,4′-diphenylmethane skeleton, a benzyl skeleton, a phenylene skeleton, a diphenyl ether skeleton, and combinations thereof. Among these, it is preferable to use a biphenyl skeleton, a 4,4'-diphenylmethane skeleton, or a viewpoint of maintaining sufficient heat resistance, further improving the flexibility of the resin composition, and further improving fluidity. Maleimide compound of benzyl skeleton. These maleimide compounds can be used individually by 1 type or in combination of 2 or more types. Among these, a maleimide compound including a biphenyl skeleton is most preferable in terms of higher heat resistance and resistance to cracks in the B-stage. The maleimide imide equivalent of the maleimide compound is preferably 100 to 1,000, more preferably 150 to 800, and still more preferably 200 to 400. By setting the maleimide imide equivalent within this range, sufficient heat resistance can be maintained, the flexibility of the resin composition is further improved, and the fluidity is further improved. The resin composition of the present invention preferably contains 25 parts by mass or more and 93 parts by mass or less with respect to 100 parts by mass of the total of the maleimide compound, the (meth) acrylic resin, and the hardening accelerator. The maleimide compound is more preferably a maleimide compound containing 28 parts by mass or more and 70 parts by mass or less, and it is more preferably a maleimide compound containing 30 parts by mass or more and 50 parts by mass or less. . By setting the blending amount of the maleimidine imine compound within this range, the flexibility of the resin composition is further improved, and the fluidity is further improved. The (meth) acrylic resin contained in the resin composition of the present invention is mainly formulated to improve the flexibility of the resin composition. In addition, it is also formulated to improve the flexibility of the resin composition by using the maleimide compound. The so-called (meth) acrylic resin-based acrylic resin and methacrylic resin are collectively referred to. (Meth) acrylic resin is a resin obtained by polymerizing acrylic acid or a derivative thereof as one of the polymerizable monomers, or a resin obtained by polymerizing methacrylic acid or a derivative thereof as one of the polymerizable monomers, or A resin obtained by polymerizing acrylic acid or a derivative thereof and methacrylic acid or a derivative thereof as a polymerizable monomer. Examples of the acrylic acid and methacrylic acid derivatives include esters of these acids or their epoxy-modified products, hydroxyl-modified products, carboxy-modified products, amine-modified products, and amido-modified products. When the (meth) acrylic resin is a copolymer including two or more kinds of repeating units, the arrangement of the repeating units in the copolymer may be random, block, or graft. When the copolymer contains a repeating unit other than (meth) acrylic acid or a derivative thereof as a copolymerization component, examples of the repeating unit include repeating units derived from acrylonitrile or repeats derived from butadiene. Units, and repeating units derived from styrene. The (meth) acrylic resin may have various functional groups at the terminal, side chain, or main chain of the polymer chain. Examples of such a functional group include a group reactive with at least one of an epoxy resin and a hardener. Specifically, for example, an epoxy group, a hydroxyl group, a carboxyl group, an amine group, and an amidino group are exemplified. When these functional groups are contained in the (meth) acrylic resin, they can react with, for example, other components contained in the resin composition. Thereby, it is expected that the heat resistance and the dimensional stability to heat of the resin composition can be achieved. Improved properties and moisture absorption resistance (solder heat resistance). Among these various functional groups, an epoxy group is particularly preferred. The (meth) acrylic resin may include a plurality of functional groups per molecule. The weight average molecular weight (hereinafter also referred to as "MW") of the (meth) acrylic resin is preferably 50,000 or more, more preferably 70,000 or more, and still more preferably 100,000 or more. The upper limit of the weight average molecular weight is preferably 1 million or less, more preferably 900,000 or less, and still more preferably 700,000 or less. By using a (meth) acrylic resin having a molecular weight in this range, sufficient flexibility can be imparted to the resin composition of the present invention, and cracks can be prevented even when a resin sheet in a B-stage state is formed. And so on. The weight average molecular weight of the (meth) acrylic resin can be analyzed, for example, by Size Exclusion Chromatography (SEC) or Gel Permeation Chromatograph (GPC) specified in JIS K7252-1: 2008. ). The resin composition of the present invention preferably contains 7 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the total of the maleimide compound, the (meth) acrylic resin, and the hardening accelerator. The (meth) acrylic resin is more preferably a (meth) acrylic resin containing 10 parts by mass or more and 60 parts by mass or less, and more preferably a (meth) containing 15 parts by mass or more and 50 parts by mass or less. Acrylic resin. By setting the compounding amount of the (meth) acrylic resin within this range, the flexibility and fluidity of the resin composition are further improved, and the heat resistance is also excellent. The hardening accelerator contained in the resin composition of the present invention is used to accelerate the hardening of the maleimide compound contained in the resin composition. The hardening accelerator is particularly preferably a compound that also accelerates the polymerization reaction (crosslinking reaction) of an epoxy group which is one type of polymerizable reactive group. Examples of such a hardening accelerator include amine compounds and phosphorus compounds. These hardening accelerators can be used individually by 1 type or in combination of 2 or more types. Among these, from the viewpoint of considering both storage stability and hardening reaction promotion, the hardening accelerator is preferably a heterocyclic aromatic amine containing a nitrogen atom in a heterocyclic ring. Among these, from the viewpoint of heat resistance and insulation reliability of the cured product, the curing accelerator is particularly preferably an imidazole-based compound. Examples of the imidazole-based compound include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-benzyl-2- Methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole and the like. In the resin composition of the present invention, it is preferable that the hardening agent contains 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total of the maleimide compound, the (meth) acrylic resin, and the hardening accelerator. The accelerator is more preferably a hardening accelerator containing 0.10 parts by mass to 5 parts by mass, and even more preferably a hardening accelerator containing 0.15 parts by mass to 3 parts by mass. By setting the compounding amount of the hardening accelerator within this range, the resin composition can be sufficiently hardened. The resin composition of the present invention contains an inorganic filler in addition to the aforementioned components. The inorganic filler is formulated to impart dimensional stability to heat to a hardened body produced from the resin composition of the present invention. Alternatively, it is formulated so as to impart moderate fluidity or flexibility to the resin composition of the present invention. Furthermore, it is formulated in order to prevent the resin composition of the present invention from blocking. The type of the inorganic filler is not particularly limited, and examples thereof include silicon dioxide, barium sulfate, calcined talc, zinc molybdate-treated talc, barium titanate, titanium oxide, clay, alumina, mica, boehmite, and zinc borate , Zinc stannate, aluminum hydroxide, calcium carbonate, magnesium hydroxide, magnesium silicate, short glass fibers, aluminum borate whiskers and silicon carbonate whiskers. These inorganic fillers may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, the inorganic filler is preferably two in terms of imparting dimensional stability to heat to the hardened body produced from the resin composition, and providing easy accessibility, heat resistance of the hardened body, and insulation reliability. Silicon oxide. As the silicon dioxide, it is known that silicon dioxide such as amorphous silicon dioxide, fused silicon dioxide, crystalline silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide can be added to the resin composition with high filling and B -From the viewpoint of good flowability (resin overflow) of the resin sheet in the staged state when heat is applied, it is particularly preferably a spherical one. The shape or size of the inorganic filler is not particularly limited. As for the shape, for example, a spherical shape, a polyhedron shape, a needle shape, a spindle shape, an irregular shape, and the like can be adopted. A combination of two or more of these shapes may be used. Regarding the size, the average particle diameter is preferably 0.001 μm or more and 20 μm or less, more preferably 0.01 μm or more and 10 μm or less, and still more preferably 0.05 μm or more and 5 μm or less. Two or more types of inorganic fillers having different average particle diameters may be used in combination, and a plurality of peaks are observed in the particle size distribution. The average particle diameter is measured based on a median diameter (D 50 ) obtained from a particle size distribution curve using a laser diffraction and scattering type particle size distribution measuring device. The ratio of the major axis to the minor axis of the particles, that is, the aspect ratio is not particularly limited. However, when the product of the present invention is manufactured, from the viewpoint of resin overflow or ease of control when imparting flexibility, the aspect ratio is preferably 1.0 or more and 10 or less, more preferably 1.0 or more and 5.0 or less, and most preferably It is preferably 1.0 or more and 2.0 or less. In terms of improving the adhesion between the resin component and the inorganic filler, and improving the moisture absorption resistance of the resin composition, the surface of the inorganic filler is preferably surface-treated with a silane coupling agent. Examples of the silane coupling agent include an amine-functional silane coupling agent, an acryl-functional silane coupling agent, a methacryl-functional silane coupling agent, an epoxy-functional silane coupling agent, and an olefin-functional silane coupling agent. Mixtures, mercapto-functional silane coupling agents, and vinyl-functional silane coupling agents. Among these, an epoxy-functional silane coupling agent, an amine-functional silane coupling agent, an acryl-functional silane coupling agent, a methacryl-functional silane coupling agent, and a vinyl-functional silane are more preferable. Coupling agent, etc. In the resin composition of the present invention, it is preferable to contain 100 parts by mass or more and 400 parts by mass or less of the total amount of the maleimide compound, the (meth) acrylic resin, and the hardening accelerator. The filler further preferably contains an inorganic filler of 100 parts by mass or more and 350 parts by mass or less, and more preferably contains an inorganic filler of 150 parts by mass or more and 300 parts by mass or less. By setting the blending amount of the inorganic filler within this range, the fluidity (resin overflow) when the heat is applied to the resin sheet in the B-stage state becomes good, and the dimensional stability of the hardened body against heat can be obtained Good heat resistance and heat resistance. The resin composition of the present invention may contain other components in addition to the components described above as necessary. Examples of other components include epoxy resins, flame retardants, flame retardant auxiliaries, coupling agents, adhesion-imparting agents, colorants, laser processability improvers, antioxidants, anti-ultraviolet deterioration agents, mold release agents, PH value adjusting agent, ion trapping agent, defoaming agent, leveling agent, anti-blocking agent, tackifier, thixotropy imparting agent and other resins other than the above resins. In particular, if the resin composition of the present invention contains an epoxy resin, the heat resistance of the hardened body is improved, the dimensional stability against heat is further improved, and the moisture absorption resistance is further improved, which is advantageous in this respect. As an epoxy resin, it can be used for a user conventionally used in this technical field without a restriction | limiting in particular. For example, naphthalene type epoxy resin, biphenylaralkyl type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S ring Oxygen resin, alicyclic epoxy resin, aliphatic chain epoxy resin, cresol novolac epoxy resin, phenol novolac epoxy resin, alkylphenol novolac epoxy resin, aralkyl ring Oxygen resin, biphenol type epoxy resin, dicyclopentadiene type epoxy resin, trihydroxybenzyl type epoxy compound, epoxide of condensate of phenols and aromatic aldehyde with phenolic hydroxyl group, bisphenol Diglycidyl etherate of naphthalene glycol, diglycidyl etherate of naphthalene glycol, diglycidyl etherate of phenol, diglycidyl etherate of alcohol, triglycidyl isocyanurate, etc. These epoxy resins can be used individually by 1 type or in combination of 2 or more types. The epoxy resin is particularly preferably a naphthalene-type epoxy resin and / or a biphenylaralkyl-type epoxy resin. By using these epoxy resins, the heat resistance of the hardened body is further improved, the dimensional stability against heat is further improved, and the moisture absorption resistance is further improved. From a viewpoint of making this effect more remarkable, it is preferable to use a naphthalene type epoxy resin as an epoxy resin. In the resin composition of the present invention, the aforesaid epoxy resin, including a naphthalene-type epoxy resin or a biphenylaralkyl-type epoxy resin, promotes hardening with respect to a maleimide compound, a (meth) acrylic resin, and the like. 100 parts by mass of the agent and the epoxy resin, preferably 10 parts by mass or more and 40 parts by mass or less, still more preferably 10 parts by mass or more and 30 parts by mass or less, further preferably 15 parts by mass Above 25 mass parts. In terms of making the cross-linking reaction of the epoxy resin more dense and improving the heat resistance of the hardened body, it is more preferable that the resin composition contains a hardening agent that is reactive with epoxy groups. Examples of such a curing agent include a diamine-based curing agent such as a primary amine or a secondary amine, a bifunctional or higher phenol compound, an acid anhydride-based curing agent, and dicyandiamide. These hardeners can be used individually by 1 type or in combination of 2 or more types. These hardeners sometimes function as hardening accelerators for the maleimide compounds described above. In this case, the hardener is positioned as a hardening accelerator. Among these, a hardening agent formed by a phenol compound, an acid anhydride-based hardening agent alone, or a combination thereof is more preferable in that the overall thermal curing reaction rate of the resin composition of the present invention can be easily controlled. The reason is that these compounds are compounds that only contribute to the hardening reaction with the epoxy resin and not to the hardening reaction of the maleimide compound, and therefore can prevent the overall thermal hardening reaction from proceeding rapidly. As a result, it is possible to prevent abnormal agglomeration of the maleimide hardened product or the epoxy hardened product in the obtained insulating layer, and therefore, the uniformity within the system can be maintained. The resin composition of the present invention can be obtained by mixing the above components in an organic solvent and stirring them. As the organic solvent, the same solvents as those previously used for the preparation of the resin composition can be used. Examples of such an organic solvent include methanol, ethanol, methyl ethyl ketone, toluene, propylene glycol monomethyl ether, dimethylformamide, dimethylacetamide, cyclohexanone, cyclopentanone, Ethyl cellosolve, 1,3-dioxolane, etc. As described above, the resin composition obtained in this manner is used for the manufacture of a printed wiring board. For example, a resin sheet for a printed wiring board containing the resin composition can be produced by forming the resin composition of the present invention into a sheet shape and drying it by heating to a semi-hardened state in the B-stage. By laminating this resin sheet, a printed wiring board can be manufactured. As an example of manufacturing a printed wiring board using the resin composition of the present invention, a resin layer obtained by curing a resin sheet can be made into an insulating layer alone. When the resin layer is made into an insulating layer alone, the thickness of the resin layer is preferably in a range of 0.5 μm or more and 200 μm or less, and more preferably in a range of 0.5 μm or more and 150 μm or less. When the thickness of the resin layer is within this range, a sufficient thickness required for insulation can be ensured, and a high flexibility can be imparted to the B-stage resin sheet. Alternatively, the resin composition of the present invention can be made into a resin composition containing the resin composition by immersing it in a fibrous substrate (cloth) such as a woven fabric, and heating and drying the impregnated body thus obtained to a semi-hardened state in the B-stage. Prepreg for printed wiring boards. By laminating the prepreg, a printed wiring board can be manufactured. The fibrous substrate is not particularly limited, but a substrate that is woven with warp and weft yarns substantially orthogonal to each other, such as plain weave, may be used. For example, a woven fabric of inorganic fibers such as glass cloth can be used. Alternatively, a woven fabric of an organic fiber such as an aromatic polyamide cloth or a polyester cloth can be used. The thickness of the fiber substrate is not particularly limited, and for example, it is preferably 10 μm or more and 200 μm or less. The resin composition of the present invention can be used as a resin sheet for a printed wiring board with a support in addition to the above-mentioned sheet or prepreg. The resin sheet is preferably one having a support and a layer of the resin composition of the present invention arranged on one side of the support. As the support, various films or foils can be used. For example, a resin film can be used as the support. Alternatively, a metal foil may be used as the support. In terms of ease of handling, the thickness of the support is preferably 5.0 μm or more and 100 μm or less. Examples of the resin film include a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, an aromatic polyimide film, a polyimide film, and a nylon film. , Liquid crystal polymer and other resin films. Metal-coated resin films having a metal layer coating on these resin films can also be used. Examples of the metal foil include a copper foil, an aluminum foil, a stainless steel foil, a nickel foil, a titanium foil, or a foil obtained by laminating a plurality of layers. In particular, MSAP (Modified Semi-Additive Process) method, SAP (Semi-Additive Process) method, or subtractive method are used as wiring pattern processing methods when forming a printed wiring board. In this case, the support is particularly preferably a metal foil and more preferably a copper foil in terms of ensuring the adhesion between the layer hardened by the resin composition and the wiring, and considering the etching processability of the metal foil. In the case where the thickness of the metal foil as a support does not reach, for example, 5.0 μm, in order to improve the operability of the metal foil with a resin layer, especially for the operation when manufacturing a printed wiring board as the metal foil with a resin layer To improve the performance, the support can also be provided with a so-called release layer and a carrier on the other side of the metal foil, and used in the form of a metal foil with a carrier. Examples of the carrier include resins such as a PET film, a PEN film, an aromatic polyimide film, a polyimide film, a nylon film, and a liquid crystal polymer, in addition to metal foils such as copper foil, nickel foil, stainless steel foil, and aluminum foil. A film, a metal-coated resin film having a metal layer coating on a resin film, and the like are typically copper foils. Examples of the release layer include an organic release layer and an inorganic release layer. Examples of the organic component used in the organic release layer include a nitrogen-containing organic compound, a sulfur-containing organic compound, and a carboxylic acid. On the other hand, examples of the inorganic component used in the inorganic release layer include Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn, and a chromate-treated film. Regarding the bonding surface between the metal foil and the resin composition layer, the surface roughness (Rzjis) based on JIS B0610-1994 is preferably 4.0 μm or less, more preferably 3.5 μm or less, and further preferably 3.0 μm or less. By setting the surface roughness (Rzjis) to this range, the unevenness on the surface of the resin layer after the metal foil is etched can be made fine. Therefore, the dimensional accuracy of the conductor layer formed on the surface of the resin layer can be made high. From the viewpoint of maintaining the adhesion between the upper conductor layer and the resin layer, the surface roughness (Rzjis) of the metal foil is preferably 0.005 μm or more, more preferably 0.01 μm or more, and still more preferably 0.05 μm or more. Furthermore, a surface treatment layer formed by a rust-proof coating treatment or the like may be formed on the surface of the metal foil. Examples of the antirust film include inorganic antirust films using zinc, nickel, and cobalt, chromate films using chromate, and organic antirust films using organic agents such as benzotriazole and imidazole. Wait. A silane layer may be formed on the surface of the surface treatment layer. By providing a silane layer, the adhesion between the surface of the metal foil and the resin layer is better. Examples of the material constituting the silane layer include a tetraalkoxysilane and a silane coupling agent. Regardless of the material of the support, the above-mentioned laminated body for a printed wiring board can be heated and pressed integrally by, for example, overlapping a sheet in a B-stage state obtained from the resin composition of the present invention with the support. And get. The heating and pressing may be performed by a vacuum pressing method or a vacuum lamination method. Alternatively, it can be obtained by coating the resin composition of the present invention on at least one side of a support and heating and drying the obtained coating film to a B-stage semi-hardened state. These resin sheets for printed wiring boards with a support can be used as the insulating layer in addition to hardening the resin sheet layer in the manner described above, and can also be used for the adhesion between the prepreg and the support (for example, metal foil). Resin coated resin layer. When used as a primer resin layer, the thickness of the resin sheet for a printed wiring board with a support is preferably 0.4 μm or more and 15 μm or less, and more preferably 0.5 μm or more and 10 μm or less. By setting it as this range, the thickness for fully improving the adhesiveness between layers can be ensured, and it can set it as the thickness suitable for microfabrication in the through-hole processing (for example, laser processing) of a printed wiring board. Between the support and the layer of the resin composition, an undercoat layer including other resin compositions may be formed as needed to improve the bonding strength between the two. The thickness of the laminated body obtained in this manner is preferably, for example, 10 μm or more and 150 μm or less. The resin sheet or prepreg or laminated system for a printed wiring board obtained in this way is formed using the resin composition of the present invention, and therefore has high dimensional stability to heat and suppresses the occurrence of cracks when an external force is applied. Therefore, these resin sheets or prepregs or laminates for printed wiring boards are particularly suitable as raw materials for manufacturing high-performance printed wiring boards. As a processing method of the printed wiring board, for example, the MSAP method, the SAP method, the subtractive method, or the like can be preferably used. In addition, printed wiring boards manufactured using these resin sheets for printed wiring boards or prepregs or laminates have high dimensional stability to heat and good high-frequency characteristics. EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to this embodiment. Unless otherwise specified, "%" means "mass%". The components used in the following examples and comparative examples are shown in Table 1 below. In addition, the blending amount of each component in the following Tables 2 to 4 is expressed in parts by mass. [Table 1] [Example 1] The components shown in Table 2 below were weighed such that the solvent was methyl ethyl ketone at the compounding ratio shown in the table, and the solid content was 60 parts by mass, and placed in The temperature of the flask was raised to 60 ° C., and the mixture was stirred for 1 hour with a propeller type stirring device to obtain a resin composition (resin varnish). Using an edge coater, apply the resin composition to the roughened surface of the copper foil with a carrier so that the thickness after drying becomes 100 μm, and heat the resin composition at 120 ° C. for 6 minutes. After drying, the solvent was evaporated to obtain a copper foil with a resin layer laminated with a resin having a semi-hardened state in the B-stage. The surface roughness (Rzjis) of the copper foil with a carrier was 1.7 μm, and the thickness was 2 μm. The copper foil with a carrier was subjected to rust prevention treatment of nickel 21 mg / m 2 , zinc 8 mg / m 2 and chromium 3 mg / m 2 , and was subjected to a surface treatment with an amine-based silane coupling agent. [Example 2] In Example 1, a resin layer was formed so that the thickness after drying became 40 μm. Except this, in the same manner as in Example 1, a copper foil with a resin layer was obtained. [Examples 3 to 14] A copper foil with a resin layer was obtained in the same manner as in Example 1 except that the resin composition was prepared as shown in Tables 2 and 3. [Comparative Example 1] As shown in Table 4, in this comparative example, the one having a lower weight average molecular weight was used as the (meth) acrylic resin. Except this, in the same manner as in Example 1, a copper foil with a resin layer was obtained. [Comparative Example 2] In this comparative example, a maleimine compound was not used. The formulation of the resin composition is shown in Table 4. Except this, in the same manner as in Example 1, a copper foil with a resin layer was obtained. [Comparative Example 3] In this Comparative Example, a (meth) acrylic resin was not used. The formulation of the resin composition is shown in Table 4. Except this, in the same manner as in Example 1, a copper foil with a resin layer was obtained. [Comparative Example 4] In this Comparative Example, instead of using a (meth) acrylic resin, a polyvinyl acetal resin was used. Except this, in the same manner as in Example 1, a copper foil with a resin layer was obtained. Polyvinyl acetal resin is a substance used as a plasticizer in this technical field. [Evaluation] The copper foil with a resin layer obtained in the examples and comparative examples was evaluated for crack prevention, blocking resistance, and resin overflow at the time of winding by the following method. In addition, the dimensional stability, glass transition point, water absorption, and dielectric characteristics (Df) of the copper foil with a resin layer obtained in the examples and comparative examples after curing were measured by the following methods. The results are shown in Tables 2 to 4 below. [Crack prevention property] A copper foil with a resin layer was cut into a size of 10 cm × 10 cm to obtain a sample piece. This sample piece was placed on a table so that the resin layer side became the lower surface side, and a cylinder with a diameter of 10 mm was arranged on the central portion of the copper foil surface on the upper surface so that the outer peripheral surface contacted the copper foil surface. The sample piece is bent upward along the cylinder. At this time, the minimum bending angle at which the resin layer was cracked (cracked) was measured. From this angle, evaluation was performed on the following criteria. AA: No rupture above 135 degrees (best) A: Rupture above 90 degrees and below 135 degrees (good) B: Rupture above 45 degrees and below 90 degrees (normal) C: Below 45 degrees The degree of cracking (poor) [Anti-blocking property] The method of contacting the copper foil with a resin layer of the same size at the resin layer to the glossy surface of a 20 cm thick copper foil with a carrier cut into 10 cm × 10 cm Overlap, apply a load of 500 g, and store in a constant temperature and humidity oven at a temperature of 30 ° C and a humidity of 40% RH for 48 hours. After that, the degree of adhesion between the resin layer and the copper foil glossy surface was evaluated based on the following criteria. A: No adhesion (good) B: Almost no adhesion (normal) C: No adhesion (poor) [Resin overflow] The so-called resin overflow is a value calculated as follows, that is, according to MIL-P in the MIL standard -13949G, from a copper foil with a resin layer set to a thickness of 40 μm, 4 pieces of 10 cm square samples were sampled, and the 4 pieces of samples were stacked (laminated) at a pressure of 171 ° C , Bonding under the conditions of a pressurizing pressure of 1.4 MPa and a pressurizing time of 10 minutes, the outflow mass of the resin at this time was measured, and the value calculated based on the following formula based on the measurement results. Based on this value, evaluation was performed based on the following criteria. Resin overflow (%) = mass of outflow resin / (mass of copper foil with resin layer 质量 mass of copper foil) × 100A: 8% or more and less than 23% (good) B: 5% or more and less than 8%, or 23% or more and less than 40% (normal) C: less than 5% or more than 40% (bad) [Dimensional stability] Two copper foils with a resin layer are laminated so that the resin layers face each other, and used Vacuum pressurization. The pressurization conditions were set at 220 ° C for 90 minutes and 1 MPa. Further, the copper foil was removed from the sample after pressing by etching. Thereby, a resin film having a thickness of about 190 μm was produced. However, Example 2 produced a resin film by the following method. Two copper foils with a resin layer were bonded together so that the resin layers faced each other, and pressed with a vacuum press. The pressing conditions were set at 120 ° C for 30 seconds and 0.7 MPa. Furthermore, the sample after pressurization was hardened | cured at 200 degreeC x 120 minutes using the oven. The copper foil of the post-hardened sample was removed by etching. Thereby, a resin film having a thickness of about 200 μm was produced. Regarding the above resin film, the thermal expansion coefficient measured according to JIS C 6481 was measured, and it was set as the standard of dimensional stability. Based on the values, evaluation was performed on the following criteria. A: Less than 20 ppm / ° C (good) B: Above 20 ppm / ° C and less than 45 ppm / ° C (normal) C: Above 45 ppm / ° C (bad) [Glass transition point] Among the terms of using dimensional stability The obtained resin film was cut into 40 mm × 5 mm. This was used as a measurement sample, and the glass transition point was measured using a dynamic viscoelasticity measuring device (DMA) (measurement conditions: tensile mode, frequency 1 Hz, temperature rise rate: 5 ° C / min). Based on the values, evaluation was performed on the following criteria. A: 260 ° C or higher (good) B: 200 ° C or higher and lower than 260 ° C (normal) C: 200 ° C or lower (bad) [Water absorption] The measurement was performed based on JIS C6481. Using the resin film obtained in the term of dimensional stability, it was cut into 50 mm × 50 mm and its mass was measured. The measurement sample was immersed in boiling water for 1 hour. After that, it was pulled out from the water, the water adhering to the surface of the measurement sample was wiped off, and then its mass was measured, and the water absorption amount was calculated from the difference between before and after immersion. Based on the values, evaluation was performed on the following criteria. A: Less than 0.7% (good) B: 0.7% or more and less than 1.2% (normal) C: 1.2% or more (bad) [Dielectric properties] Use the resin film obtained in the above [Dimensional stability] item Using a network analyzer (manufactured by Keysight, PNA-I N5234A), the dielectric loss tangent at 3 GHz was measured by the SPDR dielectric resonator method. This measurement is performed in accordance with ASTM D2520 (JIS C2565), and the measurement result is taken as the value of the dielectric loss tangent (Df). [Table 2] [table 3] [Table 4] From the results shown in Table 2 or 4, it is clear that the copper foil with a resin layer obtained by using the resin composition obtained in each example can prevent the occurrence of cracks and prevent the occurrence of blocking. Furthermore, the resin composition has good fluidity. In addition, the hardened body is excellent in dimensional stability and has a low dielectric property (Df) at high frequencies. [Industrial Applicability] According to the present invention, there is provided a resin composition for a printed wiring board having high flexibility in a B-stage state and high dimensional stability of a cured body to heat.
