本發明之一個實施形態之染色助劑含有由下述通式(1)表示之化合物作為成分(A)。成分(A)特別於聚酯纖維等化學纖維或者包含該等之混紡纖維或複合纖維等之染色中，作為擴展纖維之結晶區域、使染料容易進入纖維內之導染劑發揮作用。 [化8]式(1)中，R1
及R4
分別獨立地表示碳數1～4之烷基或烷氧基，a及c分別獨立地表示0～3之整數。於R1
或R4
有複數個之情形時，可相同，亦可不同。就均染性及染色親和性更為優異之觀點而言，作為R1
及R4
，較佳為碳數1～3之烷基。此外，就同樣之觀點而言，作為a及c，較佳為0或1，更佳0。 R2
及R3
分別獨立地表示單鍵或碳數1～3之伸烷基。就均染性及染色親和性更優異之觀點而言，作為R2
及R3
，較佳為單鍵。 A1
O表示碳數2～6之伸烷氧基，b為1～10。於A1
O有複數個之情形時，可相同，亦可不同。就均染性及染色親和性更優異之觀點而言，作為A1
O，較佳為碳數2～4之伸烷氧基。此外，就均染性及染色親和性更優異之觀點而言，作為b，較佳為1～5。 作為製造由式(1)表示之化合物之方法，例如能夠藉由使可具有烷基或烷氧基之芳香族羧酸與碳數2～4之氧化烯之聚合物或碳數2～6之鏈烷二醇反應而獲得。 作為芳香族羧酸，可列舉：苯甲酸、2-甲基苯甲酸、4-乙基苯甲酸、4-正丙基苯甲酸及4-第三丁基苯甲酸等具有碳數1～4之烷基之苯甲酸、以及2-甲氧基苯甲酸及4-第三丁氧基苯甲酸等具有碳數1～4之烷氧基之苯甲酸。作為芳香族羧酸，就均染性及染色親和性更優異之觀點而言，更佳為苯甲酸或具有碳數1～4之烷基之苯甲酸。 此外，作為碳數2～6之烷烴二醇，可列舉：乙烷-1,2-二醇、1,3-丙二醇及1,4-丁二醇等。 染色助劑中之成分(A)之含量可列舉相對於染色助劑總量為0.1～100質量%之量。作為可於染色助劑中含有之成分(A)以外之成分，例如可列舉：水、有機溶劑、及成分(A)以外之界面活性劑等。 為了例如調節染色助劑之黏度或劑料穩定性而添加有機溶劑，例如可列舉：甲醇、乙醇、異丙醇、乙二醇單丁醚、二乙二醇單丁醚等碳數1～10之醇等。其中，較佳為二乙二醇單丁醚。染色助劑中之有機溶劑之含量，相對於染色助劑總量，較佳為0.5～15質量%。 作為成分(A)以外之界面活性劑，能夠無特別限制地使用公知之界面活性劑。例如可列舉：陰離子界面活性劑、非離子界面活性劑及陽離子界面活性劑等。 作為陰離子界面活性劑，例如可列舉：脂肪醇(脂肪醇之碳數1～22)之氧化烯加成物之硫酸酯或磷酸酯或該等之鹽、由碳數2～4之氧化烯獲得之聚伸烷基二醇之硫酸酯或磷酸酯或該等之鹽、單或多苯乙烯化苯酚之氧化烯加成物之硫酸酯或磷酸酯或該等之鹽、單或多苯乙烯化烷基(烷基之碳數1～10)苯酚之氧化烯加成物之硫酸酯或磷酸酯或該等之鹽、烷基(烷基之碳數8～22)苯磺酸或其鹽、烷基(烷基之碳數8～22)磺酸或其鹽、α-烯烴磺酸(α-烯烴磺酸之碳數8～22)或其鹽、α-磺基脂肪酸烷基酯(α-磺基脂肪酸之碳數8～22、烷基之碳數1～12)或其鹽等。 作為鹽，可列舉：鹼金屬鹽、鹼土金屬鹽、銨鹽、烷醇胺鹽等。 此外，作為非離子界面活性劑，例如可列舉：脂肪醇(脂肪醇之碳數1～22)之氧化烯加成物或其脂肪酸(脂肪酸之碳數8～24)酯、由碳數2～4之氧化烯獲得之聚伸烷基二醇或其脂肪酸(脂肪酸之碳數8～24)酯、單或多苯乙烯化苯酚之氧化烯加成物或其脂肪酸(脂肪酸之碳數8～24)酯、單或多苯乙烯化烷基(烷基之碳數1～10)苯酚之氧化烯加成物之脂肪酸(脂肪酸之碳數8～24)酯等。 作為陽離子界面活性劑，例如可列舉：氯化芐烷銨、具有1個或2個長鏈烷基之三烷基胺與四級化劑之反應物、單或二烷基胺之氧化烯加成物與四級化劑之反應物、烷基吡啶鎓鹽等四級銨型界面活性劑等。作為上述三烷基胺之長鏈烷基之碳數，可列舉6～24，剩餘之烷基之碳數可列舉1～5。作為上述單或二烷基胺之烷基之碳數，可列舉6～24。作為上述氧化烯，可列舉碳數2～4之氧化烯，作為該等之加成莫耳數，可列舉2～50。作為上述四級銨化劑，例如可列舉：具有碳數1～5之烷基之烷基鹵化物或具有碳數1～5之烷基之二烷基硫酸等。作為上述烷基吡啶鎓鹽之烷基之碳數，可列舉3～24。 染色助劑中，就均染性及染色親和性更優異之觀點而言，作為成分(B)，較佳為進而含有選自由陰離子界面活性劑及非離子界面活性劑所組成之群中之至少一種之界面活性劑。 進而，於該等陰離子界面活性劑及非離子界面活性劑之中，作為成分(B)，就均染性及染色親和性更優異之觀點而言，較佳為下述化合物(B1)及/或下述化合物(B2)。 化合物(B1)為由下述通式(2)表示之化合物。 [化9]式(2)中，R5
、R6
及R7
分別獨立地表示氫原子或甲基，就均染性及染色親和性更優異之觀點而言，較佳氫原子。 d表示1～3之整數，e表示0～2之整數，f表示0～5之整數，[(d×e＋e)＋f]為1～5。就均染性及染色親和性更優異之觀點而言，[(d×e＋e)＋f]較佳為1～4，更佳為2或3。 A2
O表示碳數2～4之伸烷氧基，g為1～100之整數。於A2
O有複數個之情形時，可相同，亦可不同。就均染性及染色親和性更優異之觀點而言，作為A2
O，較佳為伸乙氧基或伸丙氧基，更佳為伸乙氧基。此外，就均染性及染色親和性更優異之觀點而言，作為g，較佳為2～50，更佳為4～20。 X表示氫原子或由下述通式(2-1)、(2-2)、(2-3)或(2-4)表示之基。 作為X為氫原子之由式(2)所示之化合物之製造方法，例如能夠藉由於單或多苯乙烯化苯酚中添加鹼催化劑(氫氧化鉀、氫氧化鈉等)，於高溫及減壓下充分地脫水後，於80～200℃下使碳數2～4之氧化烯進行加成反應而獲得。 [化10]式(2-1)中，R8
表示碳數7～23之脂肪族烴基，可為飽和，亦可為不飽和，可為直鏈狀，亦可為分支鏈狀。就均染性及染色親和性更優異之觀點而言，脂肪族烴基之碳數較佳為11～21，更佳為13～19。 作為X為由式(2-1)表示之基之式(2)之化合物之製造方法，例如能夠藉由使單或多苯乙烯化苯酚之碳數2～4之氧化烯加成物與碳數8～24之脂肪酸反應而製造。 作為碳數8～24之脂肪酸，例如可列舉：辛酸、壬酸、癸酸、十二烷酸、十四烷酸、十五烷酸、十六烷酸、9-十六碳烯酸、十七烷酸、2-庚基十一烷酸、順式-9-十八碳烯酸、11-十八碳烯酸、順,順-9,12-十八碳二烯酸等。此外，作為碳數8～24之脂肪酸，可使用來自天然物之脂肪酸，例如可列舉由妥爾油精製之妥爾油脂肪酸、將椰子油水解獲得之椰子油脂肪酸等。該等之中，就染料分散性、均染性及染色親和性更優異之觀點而言，較佳為順式-9-十八碳烯酸、妥爾油脂肪酸、順,順-9,12-十八碳二烯酸，更佳為順式-9-十八碳烯酸。 [化11][化12][化13]式(2-2)、(2-3)及(2-4)中，M1
、M2
、M3
及M4
分別獨立表示氫原子、鹼金屬原子或銨。就均染性及染色親和性更優異之觀點而言，作為M1
、M2
、M3
及M4
，較佳為銨。 作為X，就均染性及染色親和性更優異之觀點而言，較佳為氫原子或由式(2-1)表示之基，更佳為氫原子。 繼而，對(B2)進行說明。(B2)為由下述通式(3)表示之化合物。 [化14]式(3)中，R9
及R10
分別獨立地表示碳數7～23之脂肪族烴基，可為飽和，亦可為不飽和，可為直鏈狀，亦可為分支鏈狀。就均染性及染色親和性更優異之觀點而言，脂肪族烴基之碳數較佳為11～21，更佳為13～19。 A3
O表示碳數2～4之伸烷氧基，h表示1～100之整數。於A3
O有複數個之情形時，可相同，亦可不同。就均染性及染色親和性更優異之觀點而言，作為A3
O，較佳為伸乙氧基或伸丙氧基，更佳為伸乙氧基。此外，就均染性及染色親和性更優異之觀點而言，作為h，較佳為5～25。 作為由通式(3)表示之化合物之製造方法，例如能夠藉由使碳數8～24之脂肪酸、碳數2～4之氧化烯之聚合物或碳數2～4之烷烴二醇反應而獲得。 作為碳數8～24之脂肪酸，能夠例示與上述同樣之脂肪酸。作為碳數2～4之烷烴二醇，可列舉：乙烷-1,2-二醇、1,3-丙二醇、1,4-丁二醇等。 作為染色助劑中之成分(B)，於化合物(B1)及化合物(B2)之中，就均染性及染色親和性更優異之觀點而言，更佳為化合物(B1)。 染色助劑中之成分(A)與成分(B)之質量比，就均染性及染色親和性更優異之觀點而言，較佳為(A)：(B)＝20：80～98：2，更佳為30：70～90：10，進而較佳為40：60～85：15。 染色助劑中之成分(A)及成分(B)之總含量可列舉相對於染色助劑總量為0.1～100質量%之量。 繼而，對染色纖維製品之製造方法之實施形態進行說明。 作為染色纖維製品之製造方法，可列舉：包括將染色助劑附著於投入至染色處理液前之纖維後進行染色之步驟之方法(包括前處理方法之染色纖維製品之製造方法)及包括使用包含染色助劑之染色處理液對纖維進行染色之步驟之方法。 前處理方法中，作為將染色助劑附著於纖維之方法，例如，可列舉如下方法：將染色助劑原樣地或者分散於水等中而調製處理液，使用浸漬法、軋染法、噴霧法、塗佈法(塗覆(coating)法、印刷法)等方法將染色助劑附著於纖維。附著後，可使其乾燥。於浸漬法之情形時，能夠使用通常使用之染色設備，例如繩狀染色機、液流染色機、捲染機、筒子紗染色機、絞紗染色機等。此外，於塗覆法之情形時，可列舉：毛刷塗佈、輥塗裝、流動・塗佈器塗裝等方法。 作為乾燥條件，並無特別限制，可為常溫，亦可加熱。此外，較佳為乾燥之同時或乾燥後進行加熱處理。作為加熱處理之方法，例如可列舉使用拉幅機等熱定形加工機進行之方法。加熱處理之條件可為濕熱，亦可為乾熱，較佳為乾熱，作為加熱處理之溫度，較佳為120～190℃，更佳為150～170℃。 此外，作為本實施形態之染色助劑對纖維之附著量，較佳為成分(A)之附著量成為纖維之0.1～10質量%之量，更佳為成為0.5～5質量%之量。 此外，使用包含染色助劑之染色處理液對纖維進行染色之情形時，作為染色助劑於染色處理液中之添加量，可根據染料之種類等適當地調整，例如，可列舉成分(A)成為0.01～15%o.w.f.之量，更佳為成為0.3～8%o.w.f.之量。 作為染色纖維製品之製造方法，就均染性更優異之觀點而言，較佳為包含前處理方法之方法。 於染色纖維製品之製造方法中之染色處理液中添加均染劑，能夠無特別限制地使用先前公知之均染劑。作為均染劑於染色處理液中之添加量，可列舉成為0.01～15%o.w.f.之量，更佳為成為0.3～8%o.w.f.之量。 染色纖維製品之製造方法中，對成為染色對象之纖維並無特別限制，例如可列舉：天然纖維、化學纖維及該等之混紡纖維或複合纖維。作為天然纖維，可列舉：木棉、麻及羊毛等，作為化學纖維，可列舉：人造絲、銅氨纖維等再生纖維，醋酸酯等半合成纖維，聚酯、聚醯胺、丙烯腈纖維及斯潘德克斯纖維等合成纖維。作為纖維之形態，亦並無特別限制，可列舉：絲、極細纖維、編物、織物、不織布等。 染色纖維製品之製造方法，就均染性及染色親和性更優異之觀點而言，較佳為包含聚酯纖維之染色纖維製品之製造中使用。 染色對象纖維與染色處理液之浴比因目標之染色親和性等而有所不同，可列舉1：3～1：30、更佳為1：5～1：25之範圍。 作為染料，較佳為分散染料，染料使用量能夠適當地選擇，可列舉例如0.001～20%o.w.f.之量。 進而，於處理液中亦可如先前般添加用以調節pH之酸或螯合劑、成分(A)及成分(B)以外之界面活性劑等。 對使用之染色設備並無特別限制，能夠使用先前之設備，例如可列舉：液流染色機、繩狀染色機、捲染染色機、經軸染色機、筒子紗染色機、奧氏染色機、高壓噴射染色機等。 對於染色溫度與染色時間，能夠應用先前之條件，例如可列舉下述方法：將處理液加熱至約40～60℃，通常歷時約50～80分鐘(欲快速地完成染色之情形時為約30～50分鐘)慢慢地升溫，於120～135℃下進行約30～90分鐘之高溫處理。然後，較佳為進行還原洗淨等皂洗處理。 對於染色時之壓力及染色後之皂洗方法並無特別限制，能夠採用先前之方法及條件。 對於染色助劑，不僅於通常之升溫速度下之染色時，而且即便於比通常較快之升溫速度下之染色時，亦能夠獲得優異之均染性及染色親和性之染色纖維製品。因此，能夠有助於能量及作業時間之減少。此外，染色助劑能夠抑制臭氣。實施例
以下列舉實施例對本發明更詳細地說明，但本發明並不受該等實施例之任何限制。 ≪1≫染色助劑之製造 使用以下之合成例及比較合成例中獲得之化合物，獲得表1及表2之組成之染色助劑(實施例1～10、比較例1～2)。 合成例1 作為成分(A)之化合物(A-1)之合成 於具備攪拌器、溫度計、附水分離器之回流冷卻器及氮氣導入管之1 L之玻璃製反應容器中裝入150.1 g(1.0莫耳)三乙二醇、244.2 g(2.0莫耳)苯甲酸、1.22 g氧化錫、36 g二甲苯，一面以30 ml/min之流量將氮吹入反應液中，一面升溫至180℃。到達180℃後，於該溫度下進行酯化反應8～10小時。將由反應生成之水利用與二甲苯之共沸排除至反應體系外。將獲得之酯化反應物用5質量%氫氧化鈉水溶液中和後，溫水洗淨，繼而，於1.5 kPa之減壓下、於120～135℃下將殘留之二甲苯餾除，獲得由下述式表示之化合物A-1。 [化15] 化合物(A-1)(上述式中，EO表示伸乙氧基。) 合成例2 作為成分(A)之化合物(A-2)之合成 除了將150.1 g(1.0莫耳)三乙二醇替換為134 g(1.0莫耳)二丙二醇以外，與合成例1同樣地獲得由下述式表示之化合物A-2。 [化16] 化合物(A-2)[上述式中，PO表示伸丙氧基。] 合成例3 作為成分(A)之化合物(A-3)之合成 除了將150.1 g(1.0莫耳)三乙二醇替換為400 g(1.0莫耳)聚乙二醇(平均分子量400)以外，與合成例1同樣地獲得由下述式表示之化合物。 [化17] 化合物(A-3)(上述式中，EO表示伸乙氧基，p表示8～10。) 合成例4 作為成分(A)之化合物(A-4)之合成 除了將150.1 g(1.0莫耳)三乙二醇替換為90.1 g(1.0莫耳)1,4-丁二醇以外，與合成例1同樣地獲得由下述式表示之化合物。 [化18] 化合物(A-4)合成例5 作為成分(A)之化合物(A-5)之合成 除了將244.2 g(2.0莫耳)苯甲酸替換為272.3 g(2.0莫耳)苯甲酸甲酯以外，與合成例1同樣地獲得由下述式表示之化合物。 [化19] 化合物(A-5)合成例6 作為成分(B)之化合物(B1-1)之合成 將三苯乙烯化苯酚之氧化乙烯加成物(平均加成莫耳數20)用作B1-1。 合成例7 作為成分(B)之化合物(B1-2)之合成 將單苯乙烯化苯酚之氧化乙烯加成物(平均加成莫耳數20)之順式-9-十八碳烯酸酯用作B1-2。 合成例8 作為成分(B)之化合物(B1-3)之合成 將三苯乙烯化苯酚之氧化乙烯加成物(平均加成莫耳數10)之硫酸酯之銨鹽用作B1-3。 合成例9 作為成分(B)之化合物(B2-1)之合成 將聚乙二醇(平均分子量800)之順式-9-十八碳烯酸二酯用作B2-1。 比較合成例1 化合物(A')之合成 除了將150.1 g(1.0莫耳)三乙二醇替換為600 g(1.0莫耳)聚乙二醇(平均分子量600)以外，與合成例1同樣地獲得由下述式表示之化合物。 [化20] 化合物(A')(上述式中，EO表示伸乙氧基，q表示13或14。) ≪2≫評價 採用以下之方法，對於各實施例1～10及比較例1～2之染色助劑，對(I)臭氣、(II)染色親和性及均染性進行評價。 (I)臭氣 調製實施例及比較例之染色助劑之1質量%水溶液，裝入密閉容器中，於80℃下靜置10分鐘。然後，對於將密閉容器開封時之臭氣根據以下之標準進行評價。將其結果示於表1及表2。 A：完全未感覺到臭氣。 B：略微感覺到臭氣。 C：明顯地感覺到臭氣。 (II)染色親和性及均染性 採用下述染色方法1或染色方法2獲得染色纖維製品。再者，對於比較例6及9，未使用染色助劑進行染色。 (II)-1.染色方法1 在Minicolour染色機(Rapid製造)之罐中，使用水調製下述組成之染色處理液，以浴比1：10向其中投入作為染色對象纖維之聚酯塔夫綢精練布(30旦，單位面積重量：50 g/m2
)，於下述條件i或條件ii下進行染色處理。 ＜染色處理液組成＞ ・實施例及比較例之染色助劑 1 g/L ・均染劑 0.5 g/L [均染劑組成] ・聚乙二醇(平均分子量800)之順式-9-十八碳烯酸二酯 45質量% ・三苯乙烯化苯酚之氧化乙烯加成物(平均加成莫耳數10)之硫酸酯之銨鹽 45質量% ・二乙二醇單丁醚 5質量% ・水 5質量% ・pH調節劑 0.3 g/L 冰醋酸 ・分散染料 各0.3%o.w.f. ・Dianix Yellow Brown XF(德司達製造，商品名) ・Dianix Rubine XFN(德司達製造，商品名) ・Dianix Navy XF(德司達製造，商品名) ＜染色條件＞ [表1] ・條件i：所需時間，合計100分鐘
[表2] ・條件ii：所需時間，合計70分鐘
染色處理後，將處理液冷卻至約80℃，將染色對象纖維取出。以浴比1：30將該等投入下述組成之還原洗淨液中，於80℃下還原洗淨15分鐘。然後，進行水洗、脫水及乾燥，獲得染色纖維製品(實施例11～20、比較例4～6)。 ＜還原洗淨液組成＞ ・SUNMORL M-240(浙江日華化學製造，商品名) 1 g/L ・碳酸鈉 1 g/L ・連二亞硫酸鈉 1 g/L (II)-2.染色方法2(前處理方法) 與水混合以使實施例及比較例之染色助劑之濃度成為2.5質量%，調製處理液。將聚酯塔夫綢精練布(30旦，單位面積重量：50 g/m2
)浸漬於其中，用軋液機擠壓以使軋液率成為40質量%，然後，於120℃下乾燥2分鐘，繼而，於150℃下乾熱處理1分鐘。染色助劑於聚酯塔夫綢精練布之附著量為聚酯塔夫綢精練布之1質量%。 然後，除了如下所述改變染色處理液組成以外，採用與上述之「(II)-1.染色方法1」同樣之方法進行染色，獲得染色纖維製品(實施例21～30、比較例7～9)。 ＜染色處理液組成＞ ・均染劑 0.5 g/L [均染劑組成] ・聚乙二醇(平均分子量800)之順式-9-十八碳烯酸二酯 45質量% ・三苯乙烯化苯酚之氧化乙烯加成物(平均加成莫耳數10)之硫酸酯之銨鹽 45質量% ・二乙二醇單丁醚 5質量% ・水 5質量% ・pH調節劑 0.3 g/L 冰醋酸 ・分散染料 各0.3%o.w.f. ・Dianix Yellow Brown XF(德司達製造，商品名) ・Dianix Rubine XFN(德司達製造，商品名) ・Dianix Navy XF(德司達製造，商品名) (II)-3.染色親和性之評價 對於獲得之染色纖維製品，使用分光測色計(CM-3600d，柯尼卡美能達股份有限公司製造)，求出400～700 nm之每10 nm之K/S值，算出其積分值，作為該染色纖維製品之K/S值。 求出將比較例6條件i獲得之染色纖維製品之K/S值設為100時之其他染色纖維製品之K/S值，作為吸色率。將其結果示於表1及表2。吸色率越高，表示越能夠濃濃地染色，即染色親和性優異。 (II)-4.均染性之評價 對獲得之染色纖維製品目視觀察，根據下述標準評價均染性。將其結果示於表1及表2。 ＜評價標準＞ A：幾乎未發現染斑，均染性良好 B：僅發現少量染斑，均染性略微良好 C：略微發現染斑，均染性略微不充分 D：發現大量染斑，均染性不充分 [表3] 表1
[表4] 表2
如表1及表2中所示，可知對於本發明之一個實施形態之染色助劑而言，來自該助劑之臭氣得到抑制。此外可知，藉由使用本發明之一個實施形態之染色助劑，能夠製造優異之均染性及染色親和性之染色纖維製品。 此外可知，即便於使升溫速度比通常較快之情形時亦能夠製造優異之均染性及染色親和性之染色纖維製品。 [產業上之可利用性] 本發明之一個實施形態之染色助劑由於臭氣小，因此來自該助劑之臭氣附著於染色對象纖維之虞較小，能夠使染色之作業環境良好。此外，藉由使用本發明之染色助劑，能夠製造優異之均染性及染色親和性之染色纖維製品。因此，即便為包含均勻地染色困難之混紡纖維、複合纖維及極細纖維之纖維製品等，亦能夠均勻地染色。 此外，本發明之一個實施形態之染色助劑中，即便於使升溫速度比通常較快之情形時，亦能夠製造優異之均染性及染色親和性之染色纖維製品。因此，能夠有助於節能及作業時間之縮短，亦能夠有助於成本減少。The dyeing assistant according to one embodiment of the present invention contains a compound represented by the following formula (1) as the component (A). The component (A) is particularly useful as a dyeing agent for expanding the crystal region of the expanded fiber and the dyeing agent which easily enters the fiber, in the dyeing of the chemical fiber such as polyester fiber or the blended fiber or the composite fiber. [化8] In the formula (1), R 1 and R 4 each independently represent an alkyl group or alkoxy group having 1 to 4 carbon atoms, and a and c each independently represent an integer of 0 to 3. When there are a plurality of cases where R 1 or R 4 is plural, they may be the same or different. From the viewpoint of more excellent leveling property and dyeing affinity, R 1 and R 4 are preferably an alkyl group having 1 to 3 carbon atoms. Further, from the same viewpoint, as a and c, it is preferably 0 or 1, more preferably 0. R 2 and R 3 each independently represent a single bond or an alkylene group having 1 to 3 carbon atoms. From the viewpoint of more excellent leveling property and dyeing affinity, R 2 and R 3 are preferably a single bond. A 1 O represents an alkylene group having 2 to 6 carbon atoms, and b is 1 to 10. When there are a plurality of A 1 O, they may be the same or different. From the viewpoint of more excellent leveling property and dyeing affinity, A 1 O is preferably an alkoxy group having 2 to 4 carbon atoms. Further, from the viewpoint of more excellent leveling property and dyeing affinity, b is preferably from 1 to 5. As a method of producing the compound represented by the formula (1), for example, a polymer having an alkyl group or an alkoxy group and a polymer having an alkylene oxide having 2 to 4 carbon atoms or a carbon number of 2 to 6 can be used. Obtained by alkanediol reaction. Examples of the aromatic carboxylic acid include benzoic acid, 2-methylbenzoic acid, 4-ethylbenzoic acid, 4-n-propylbenzoic acid, and 4-tert-butylbenzoic acid having a carbon number of 1 to 4. A benzoic acid having an alkyl group having 1 to 4 carbon atoms such as a benzoic acid of an alkyl group or a 2-methoxybenzoic acid or a 4-tert-butoxybenzoic acid. The aromatic carboxylic acid is more preferably benzoic acid or benzoic acid having an alkyl group having 1 to 4 carbon atoms from the viewpoint of more excellent leveling property and dyeing affinity. Further, examples of the alkanediol having 2 to 6 carbon atoms include ethane-1,2-diol, 1,3-propanediol, and 1,4-butanediol. The content of the component (A) in the dyeing assistant is, for example, an amount of from 0.1 to 100% by mass based on the total amount of the dyeing assistant. Examples of the component other than the component (A) which can be contained in the dyeing auxiliary agent include water, an organic solvent, and a surfactant other than the component (A). The organic solvent is added, for example, to adjust the viscosity of the dyeing aid or the stability of the coating material, and examples thereof include carbon numbers 1 to 10 such as methanol, ethanol, isopropanol, ethylene glycol monobutyl ether, and diethylene glycol monobutyl ether. Alcohol and so on. Among them, diethylene glycol monobutyl ether is preferred. The content of the organic solvent in the dyeing assistant is preferably from 0.5 to 15% by mass based on the total amount of the dyeing assistant. As the surfactant other than the component (A), a known surfactant can be used without particular limitation. For example, an anionic surfactant, a nonionic surfactant, a cationic surfactant, etc. are mentioned. Examples of the anionic surfactant include a sulfate or a phosphate ester of an alkylene oxide adduct of a fatty alcohol (having a carbon number of a fatty alcohol of 1 to 22) or a salt thereof, which is obtained from an alkylene oxide having 2 to 4 carbon atoms. a sulfate or phosphate of an alkyl diol or a salt or a phosphate of the alkylene oxide adduct of the mono or polystyrenated phenol or a salt thereof, mono- or polystyrenated Alkyl group (carbon number of alkyl group: 1 to 10), a sulfate or phosphate of an alkylene oxide adduct of phenol or a salt thereof, an alkyl group (carbon number of alkyl group: 8 to 22), benzenesulfonic acid or a salt thereof, Alkyl (alkyl group 8 to 22) sulfonic acid or a salt thereof, α-olefin sulfonic acid (carbon number 8 to 22 of α-olefin sulfonic acid) or a salt thereof, α-sulfofatty acid alkyl ester (α) - a sulfo fatty acid having 8 to 22 carbon atoms and an alkyl group having 1 to 12 carbon atoms or a salt thereof. The salt may, for example, be an alkali metal salt, an alkaline earth metal salt, an ammonium salt or an alkanolamine salt. Further, examples of the nonionic surfactant include an alkylene oxide adduct of a fatty alcohol (carbon number of the aliphatic alcohol: 1 to 22) or a fatty acid (carbon number 8 to 24 of a fatty acid) ester, and a carbon number of 2 to a polyalkylene glycol obtained by alkylene oxide or a fatty acid thereof (carbon number 8 to 24 of a fatty acid) ester, an alkylene oxide adduct of a mono- or polystyrenated phenol or a fatty acid thereof (carbon number of fatty acid 8 to 24) An ester, a mono- or polystyrylalkyl group (having an alkyl group having 1 to 10 carbon atoms), an alkylene oxide adduct of a phenol, a fatty acid (carbon number of a fatty acid of 8 to 24), or the like. Examples of the cationic surfactant include a benzalkonium chloride, a reaction of a trialkylamine having one or two long-chain alkyl groups with a quaternizing agent, and an alkylene oxide of a mono- or dialkylamine. A reaction product of a product and a quaternizing agent, a quaternary ammonium type surfactant such as an alkylpyridinium salt, or the like. The carbon number of the long-chain alkyl group of the trialkylamine may be 6 to 24, and the number of carbon atoms of the remaining alkyl group may be 1 to 5. The carbon number of the alkyl group of the above mono or dialkylamine is 6 to 24. Examples of the alkylene oxide include an alkylene oxide having 2 to 4 carbon atoms, and examples of the number of addition moles include 2 to 50. Examples of the quaternary ammonating agent include an alkyl halide having an alkyl group having 1 to 5 carbon atoms or a dialkyl sulfuric acid having an alkyl group having 1 to 5 carbon atoms. The carbon number of the alkyl group of the above alkyl pyridinium salt is 3 to 24. In the dyeing assistant, it is preferable that the component (B) further contains at least one selected from the group consisting of an anionic surfactant and a nonionic surfactant, from the viewpoint of further improving the leveling property and the dyeing affinity. A surfactant. Further, among the anionic surfactants and the nonionic surfactants, the component (B) is preferably the following compound (B1) and/or from the viewpoint of further improving the leveling property and the dyeing affinity. Or the following compound (B2). The compound (B1) is a compound represented by the following formula (2). [Chemistry 9] In the formula (2), R 5 , R 6 and R 7 each independently represent a hydrogen atom or a methyl group, and a hydrogen atom is preferred from the viewpoint of more excellent dyeing property and dyeing affinity. d represents an integer of 1 to 3, e represents an integer of 0 to 2, f represents an integer of 0 to 5, and [(d × e + e) + f] is 1 to 5. From the viewpoint of more excellent leveling property and dyeing affinity, [(d × e + e) + f] is preferably from 1 to 4, more preferably 2 or 3. A 2 O represents an alkyleneoxy group having 2 to 4 carbon atoms, and g is an integer of 1 to 100. When there are a plurality of A 2 O, they may be the same or different. From the viewpoint of more excellent leveling property and dyeing affinity, as A 2 O, an ethoxy group or a propenoxy group is preferred, and an ethoxy group is more preferred. Further, from the viewpoint of more excellent leveling property and dyeing affinity, g is preferably from 2 to 50, more preferably from 4 to 20. X represents a hydrogen atom or a group represented by the following formula (2-1), (2-2), (2-3) or (2-4). The method for producing a compound represented by the formula (2) wherein X is a hydrogen atom can be, for example, a base catalyst (potassium hydroxide, sodium hydroxide or the like) added to a mono- or polystyrenated phenol at a high temperature and a reduced pressure. After sufficiently dehydrating, it is obtained by subjecting an alkylene oxide having 2 to 4 carbon atoms to an addition reaction at 80 to 200 °C. [化10] In the formula (2-1), R 8 represents an aliphatic hydrocarbon group having 7 to 23 carbon atoms, and may be saturated or unsaturated, and may be linear or branched. The carbon number of the aliphatic hydrocarbon group is preferably from 11 to 21, more preferably from 13 to 19, from the viewpoint of more excellent leveling property and dyeing affinity. The method for producing a compound of the formula (2) wherein X is a group represented by the formula (2-1), for example, an alkylene oxide adduct having a carbon number of 2 to 4 by mono or polystyryl phenol and carbon can be used. The fatty acids of 8 to 24 are produced by reaction. Examples of the fatty acid having 8 to 24 carbon atoms include caprylic acid, capric acid, capric acid, dodecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, 9-hexadecenoic acid, and ten. Heptadecanoic acid, 2-heptylundecanoic acid, cis-9-octadecenoic acid, 11-octadecenoic acid, cis, cis-9,12-octadecadienoic acid and the like. Further, as the fatty acid having 8 to 24 carbon atoms, a fatty acid derived from a natural product can be used, and examples thereof include tall oil fatty acid purified from tall oil and coconut fatty acid obtained by hydrolyzing coconut oil. Among these, cis-9-octadecenoic acid, tall oil fatty acid, cis, cis-9, 12 are preferable from the viewpoint of more excellent dye dispersibility, leveling property, and dye affinity. - octadecadienoic acid, more preferably cis-9-octadecenoic acid. [11] [化12] [Chemistry 13] In the formulae (2-2), (2-3) and (2-4), M 1 , M 2 , M 3 and M 4 each independently represent a hydrogen atom, an alkali metal atom or ammonium. From the viewpoint of more excellent leveling property and dyeing affinity, as M 1 , M 2 , M 3 and M 4 , ammonium is preferred. X is preferably a hydrogen atom or a group represented by the formula (2-1) from the viewpoint of more excellent dyeing property and dye affinity, and more preferably a hydrogen atom. Next, (B2) will be described. (B2) is a compound represented by the following formula (3). [Chemistry 14] In the formula (3), R 9 and R 10 each independently represent an aliphatic hydrocarbon group having 7 to 23 carbon atoms, and may be saturated or unsaturated, and may be linear or branched. The carbon number of the aliphatic hydrocarbon group is preferably from 11 to 21, more preferably from 13 to 19, from the viewpoint of more excellent leveling property and dyeing affinity. A 3 O represents an alkylene group having 2 to 4 carbon atoms, and h represents an integer of 1 to 100. When there are a plurality of A 3 O, they may be the same or different. From the viewpoint of more excellent leveling property and dyeing affinity, as A 3 O, an ethoxy group or a propenyloxy group is preferred, and an ethoxy group is more preferred. Further, from the viewpoint of more excellent leveling property and dyeing affinity, it is preferably 5 to 25 as h. The method for producing the compound represented by the formula (3) can be, for example, by reacting a fatty acid having 8 to 24 carbon atoms, a polymer having 2 to 4 carbon atoms or an alkanediol having 2 to 4 carbon atoms. obtain. As the fatty acid having 8 to 24 carbon atoms, the same fatty acid as described above can be exemplified. Examples of the alkanediol having 2 to 4 carbon atoms include ethane-1,2-diol, 1,3-propanediol, and 1,4-butanediol. In the compound (B1) and the compound (B2), the compound (B1) is more preferable because the leveling property and the dyeing affinity are more excellent. The mass ratio of the component (A) to the component (B) in the dyeing assistant is preferably (A): (B) = 20: 80 to 98 in terms of uniformity of dyeing property and dyeing affinity. 2, more preferably 30:70 to 90:10, and still more preferably 40:60 to 85:15. The total content of the component (A) and the component (B) in the dyeing assistant is, for example, an amount of from 0.1 to 100% by mass based on the total amount of the dyeing assistant. Next, an embodiment of a method for producing a dyed fiber product will be described. Examples of the method for producing the dyed fiber product include a method of attaching a dyeing assistant to a fiber before being fed to a dyeing treatment liquid, followed by a step of dyeing (including a method for producing a dyed fiber product including a pretreatment method), and including A method of dyeing a fiber by a dyeing treatment liquid of a dyeing assistant. In the pretreatment method, as a method of attaching the dyeing aid to the fiber, for example, a method of preparing the treatment liquid by dispersing the dyeing aid as it is or by dispersing it in water or the like, and using the dipping method, the padding method, and the spraying method A dyeing aid is attached to the fiber by a coating method (coating method, printing method) or the like. After attachment, it can be dried. In the case of the dipping method, it is possible to use a dyeing apparatus which is generally used, such as a rope dyeing machine, a liquid dyeing machine, a jig dyeing machine, a cheese dyeing machine, a hank dyeing machine, and the like. Further, in the case of the coating method, methods such as brush coating, roll coating, and flow/applicator coating may be mentioned. The drying conditions are not particularly limited, and may be normal temperature or may be heated. Further, it is preferred to carry out heat treatment while drying or after drying. As a method of heat treatment, for example, a method using a heat setting machine such as a tenter is used. The heat treatment may be carried out by moist heat or dry heat, preferably dry heat, and the temperature of the heat treatment is preferably from 120 to 190 ° C, more preferably from 150 to 170 ° C. In addition, the adhesion amount of the dyeing aid to the fiber of the present embodiment is preferably such that the amount of the component (A) adheres is 0.1 to 10% by mass of the fiber, and more preferably 0.5 to 5% by mass. In addition, when the fiber is dyed with a dyeing treatment liquid containing a dyeing aid, the amount of the dyeing aid to be added to the dyeing treatment liquid can be appropriately adjusted depending on the type of the dye, etc., for example, the component (A) It is an amount of 0.01 to 15% owf, more preferably 0.3 to 8% owf. As a method of producing a dyed fiber product, a method including a pretreatment method is preferred from the viewpoint of further improving the leveling property. A leveling agent is added to the dyeing treatment liquid in the method for producing a dyed fiber product, and a previously known leveling agent can be used without particular limitation. The amount of the leveling agent added to the dyeing treatment liquid is, for example, an amount of 0.01 to 15% owf, more preferably 0.3 to 8% owf. In the method for producing a dyed fiber product, the fiber to be dyed is not particularly limited, and examples thereof include natural fibers, chemical fibers, and blended fibers or composite fibers. Examples of the natural fiber include kapok, hemp, and wool. Examples of the chemical fiber include regenerated fibers such as rayon and copper ammonia fiber, semisynthetic fibers such as acetate, and polyester, polyamide, and acrylonitrile fibers. Synthetic fibers such as Pendex fiber. The form of the fiber is not particularly limited, and examples thereof include silk, ultrafine fibers, knitted fabrics, woven fabrics, and non-woven fabrics. The method for producing a dyed fiber product is preferably used for the production of a dyed fiber product comprising a polyester fiber from the viewpoint of more excellent leveling property and dyeing affinity. The bath ratio of the dyed target fiber to the dyeing treatment liquid differs depending on the dyeing affinity of the target, and is, for example, 1:3 to 1:30, more preferably 1:5 to 1:25. The dye is preferably a disperse dye, and the amount of the dye used can be appropriately selected, and examples thereof include an amount of 0.001 to 20% owf. Further, an acid or a chelating agent for adjusting the pH, a surfactant other than the component (A) and the component (B), and the like may be added to the treatment liquid as before. The dyeing equipment to be used is not particularly limited, and the prior equipment can be used, and examples thereof include a liquid dyeing machine, a rope dyeing machine, a dyeing and dyeing machine, a warp beam dyeing machine, a cheese dyeing machine, an austenite dyeing machine, and the like. High pressure jet dyeing machine, etc. For the dyeing temperature and the dyeing time, the previous conditions can be applied. For example, the method may be mentioned: heating the treatment liquid to about 40 to 60 ° C, usually for about 50 to 80 minutes (about 30 for the case where the dyeing is to be completed quickly) ～50 minutes) The temperature was gradually raised, and the temperature was elevated at 120 to 135 ° C for about 30 to 90 minutes. Then, it is preferred to carry out a soaping treatment such as reduction washing. The pressure at the time of dyeing and the soaping method after dyeing are not particularly limited, and the previous methods and conditions can be employed. For the dyeing assistant, it is possible to obtain a dyed fiber product having excellent leveling property and dyeing affinity, not only at the usual dyeing speed, but also at a temperature higher than the usual temperature. Therefore, it is possible to contribute to a reduction in energy and work time. In addition, the dyeing aid can suppress odor. EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples. Manufacture of the dyeing aids The dyeing assistants (Examples 1 to 10 and Comparative Examples 1 and 2) having the compositions of Tables 1 and 2 were obtained by using the following synthesis examples and the compounds obtained in the comparative synthesis examples. Synthesis Example 1 Synthesis of Compound (A-1) as Component (A) In a glass reaction vessel equipped with a stirrer, a thermometer, a reflux condenser with a water separator, and a nitrogen gas introduction tube, 150.1 g ( 1.0 mol) triethylene glycol, 244.2 g (2.0 mol) benzoic acid, 1.22 g tin oxide, 36 g xylene, and nitrogen was blown into the reaction solution at a flow rate of 30 ml/min, and the temperature was raised to 180 ° C. . After reaching 180 ° C, the esterification reaction was carried out at this temperature for 8 to 10 hours. The water produced by the reaction is removed from the reaction system by azeotropy with xylene. The obtained esterification reaction product was neutralized with a 5 mass% sodium hydroxide aqueous solution, and then washed with warm water, and then the residual xylene was distilled off at 120 to 135 ° C under a reduced pressure of 1.5 kPa to obtain Compound A-1 represented by the following formula. Compound (A-1) (In the above formula, EO represents an ethoxy group.) Synthesis Example 2 Synthesis of the compound (A-2) as the component (A) except that 150.1 g (1.0 mol) of triethylene glycol was replaced with 134 g (1.0 mol) In the same manner as in Synthesis Example 1, the compound A-2 represented by the following formula was obtained, except for the di) propylene glycol. Compound (A-2) [In the above formula, PO represents a propoxy group. Synthesis Example 3 Synthesis of Compound (A-3) as Component (A): In addition to replacing 150.1 g (1.0 mol) of triethylene glycol with 400 g (1.0 mol) of polyethylene glycol (average molecular weight of 400) The compound represented by the following formula was obtained in the same manner as in Synthesis Example 1. Compound (A-3) (In the above formula, EO represents an ethoxy group, and p represents 8 to 10.) Synthesis Example 4 Synthesis of the compound (A-4) as the component (A) except that 150.1 g (1.0 mol) of triethylene glycol was replaced A compound represented by the following formula was obtained in the same manner as in Synthesis Example 1, except that 90.1 g (1.0 mol) of 1,4-butanediol was used. Compound (A-4) Synthesis Example 5 Synthesis of Compound (A-5) as Component (A) was obtained in the same manner as in Synthesis Example 1 except that 244.2 g (2.0 mol) of benzoic acid was replaced with 272.3 g (2.0 mol) of methyl benzoate. A compound represented by the following formula. Compound (A-5) Synthesis Example 6 Synthesis of Compound (B1-1) as Component (B) An ethylene oxide adduct of tristyrenated phenol (average addition molar number of 20) was used as B1-1. Synthesis Example 7 Synthesis of Compound (B1-2) as Component (B) An oxyethylene oxide adduct of monostyrenated phenol (average addition of mole number 20) of cis-9-octadecenoate Used as B1-2. Synthesis Example 8 Synthesis of Compound (B1-3) as Component (B) An ammonium salt of a sulfuric acid ester of an ethylene oxide adduct of tristyrenated phenol (average addition molar number of 10) was used as B1-3. Synthesis Example 9 Synthesis of Compound (B2-1) as Component (B) A cis-9-octadecenoic acid diester of polyethylene glycol (having an average molecular weight of 800) was used as B2-1. Comparative Synthesis Example 1 Synthesis of Compound (A') In the same manner as in Synthesis Example 1, except that 150.1 g (1.0 mol) of triethylene glycol was replaced by 600 g (1.0 mol) of polyethylene glycol (average molecular weight of 600). A compound represented by the following formula is obtained. Compound (A') (In the above formula, EO represents an ethoxy group, and q represents 13 or 14.) ≪2≫ Evaluation The dyeing auxiliaries of the respective Examples 1 to 10 and Comparative Examples 1 and 2 were subjected to the following methods, and (I) Odor, (II) dyeing affinity and leveling property were evaluated. (I) A 1% by mass aqueous solution of the dyeing assistant of the examples and the comparative examples was placed in a sealed container and allowed to stand at 80 ° C for 10 minutes. Then, the odor at the time of opening the sealed container was evaluated according to the following criteria. The results are shown in Tables 1 and 2. A: No smell is felt at all. B: Slightly felt odor. C: The odor is clearly felt. (II) Dyeing affinity and leveling property A dyed fiber product was obtained by the following dyeing method 1 or dyeing method 2. Further, for Comparative Examples 6 and 9, dyeing was not carried out using a dyeing assistant. (II)-1. Dyeing method 1 In a jar of a Minicolour dyeing machine (manufactured by Rapid), a dyeing treatment liquid having the following composition was prepared using water, and a polyester taffeta as a dyeing target fiber was introduced thereto at a bath ratio of 1:10. A silk scouring cloth (30 denier, basis weight: 50 g/m 2 ) was subjected to dyeing treatment under the following condition i or condition ii. <Composition of dyeing treatment liquid> ・Dyeing aid 1 g/L of the examples and comparative examples ・Leveling agent 0.5 g/L [Material composition] ・Glycol (average molecular weight: 800) cis-9- Ethyl octenoic acid diester 45 mass% ・Ethylene oxide adduct of tristyrenated phenol (average addition molar number 10) ammonium salt of 45% by mass ・Diethylene glycol monobutyl ether 5 mass % ・Water 5 mass% ・pH adjuster 0.3 g/L glacial acetic acid ・disperse dye 0.3% owf ・Dianix Yellow Brown XF (made by DyStar), Dianix Rubine XFN (made by DyStar)・Dianix Navy XF (made by DyStar), <Dyeing conditions> [Table 1] ・Condition i: Time required, total 100 minutes [Table 2] ・Condition ii: Time required, total 70 minutes After the dyeing treatment, the treatment liquid was cooled to about 80 ° C, and the dyed fiber was taken out. These were put into a reducing washing liquid having the following composition at a bath ratio of 1:30, and washed at 80 ° C for 15 minutes. Then, washing with water, dehydration, and drying were carried out to obtain dyed fiber products (Examples 11 to 20 and Comparative Examples 4 to 6). <Reduction washing composition> ・SUNMORL M-240 (Zhejiang Rihua Chemical Co., Ltd., trade name) 1 g/L ・Sodium carbonate 1 g/L ・Sodium dithionite 1 g/L (II)-2. Dyeing method 2 (Pretreatment method) The mixture was mixed with water so that the concentration of the dyeing auxiliary of the examples and the comparative examples was 2.5% by mass, and the treatment liquid was prepared. A polyester taffeta scouring cloth (30 denier, basis weight: 50 g/m 2 ) was immersed therein, and pressed with a rolling mill to make the liquid-rolling rate 40% by mass, and then dried at 120 ° C. 2 Minutes, then, dry heat treatment at 150 ° C for 1 minute. The adhesion amount of the dyeing assistant to the polyester taffeta scouring cloth is 1% by mass of the polyester taffeta scouring cloth. Then, dyeing was carried out in the same manner as in the above-mentioned "(II)-1. Dyeing Method 1" except that the composition of the dyeing treatment liquid was changed as described below (Examples 21 to 30, Comparative Examples 7 to 9). ). <Composition of dyeing treatment liquid> ・Material dyeing agent 0.5 g/L [Material composition of leveling agent] ・45% by mass of cis-9-octadecenoic acid diester of polyethylene glycol (average molecular weight of 800) ・Tristyrene Ammonium oxide of phenolic oxyethylene adduct (average addition molar number of 10) 45 mass% of ammonium sulfate ・5 mass% of diethylene glycol monobutyl ether ・5 mass% of water ・pH adjuster 0.3 g/L Glacial acetic acid and disperse dyes each 0.3% owf ・Dianix Yellow Brown XF (made by DyStar, trade name) ・Dianix Rubine XFN (made by DyStar), Dianix Navy XF (made by DyStar) II)-3. Evaluation of dye affinity For the obtained dyed fiber product, a K/S value of 10 nm from 400 to 700 nm was obtained using a spectrophotometer (CM-3600d, manufactured by Konica Minolta Co., Ltd.), and the integral value was calculated. As the K/S value of the dyed fiber product. The K/S value of the other dyed fiber product when the K/S value of the dyed fiber product obtained in Condition i of Comparative Example 6 was 100 was determined as the color absorption ratio. The results are shown in Tables 1 and 2. The higher the color absorption ratio, the more intense the dyeing is, that is, the dyeing affinity is excellent. (II)-4. Evaluation of the leveling property The obtained dyed fiber product was visually observed, and the leveling property was evaluated according to the following criteria. The results are shown in Tables 1 and 2. <Evaluation Criteria> A: No staining was observed, and the dyeing property was good. B: Only a small amount of stains were found, and the dyeing properties were slightly good. C: Spots were slightly found, and the dyeing was slightly insufficient. D: A large number of stains were found. Insufficient dyeing [Table 3] Table 1 [Table 4] Table 2 As shown in Tables 1 and 2, it is understood that the dyeing aid of one embodiment of the present invention is suppressed from the odor of the auxiliary. Further, it is understood that a dyed fiber product excellent in leveling property and dyeing affinity can be produced by using the dyeing auxiliary of one embodiment of the present invention. Further, it has been found that a dyed fiber product having excellent leveling property and dyeing affinity can be produced even when the temperature increase rate is faster than usual. [Industrial Applicability] Since the dyeing aid according to the embodiment of the present invention has a small odor, the odor from the auxiliary agent adheres to the fiber to be dyed, and the working environment of the dyeing can be improved. Further, by using the dyeing assistant of the present invention, it is possible to produce a dyed fiber product excellent in leveling property and dyeing affinity. Therefore, it is possible to uniformly dye even a fiber product including a blended fiber, a composite fiber, and an ultrafine fiber which are difficult to uniformly dye. Further, in the dyeing assistant according to the embodiment of the present invention, it is possible to produce a dyed fiber product having excellent leveling property and dyeing affinity even when the temperature increase rate is faster than usual. Therefore, it is possible to contribute to energy saving and shortening of work time, and it is also possible to contribute to cost reduction.