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Title:
COATED PAPER AND PAPERBOARD STRUCTURES
Document Type and Number:
WIPO Patent Application WO/2021/126477
Kind Code:
A1
Abstract:
A coated paper or paperboard structure includes a paper or paperboard substrate and a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface. The basecoat includes a water-soluble polymer binder and pigment.

Inventors:
BUSHHOUSE STEVEN (US)
FUGITT GARY (US)
GINTHER SCOTT (US)
Application Number:
PCT/US2020/061738
Publication Date:
June 24, 2021
Filing Date:
November 23, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
WESTROCK MWV LLC (US)
International Classes:
D21H19/36; D21H19/50; D21H19/52; D21H19/54; D21H27/10
Domestic Patent References:
WO2005113894A12005-12-01
WO2014086983A12014-06-12
Foreign References:
JPS56398A1981-01-06
US20170328005A12017-11-16
US201962949012P2019-12-17
EP1375612A12004-01-02
US20160017166A12016-01-21
Attorney, Agent or Firm:
WASYLYNA, Victor, J. (US)
Download PDF:
Claims:
What is Claimed is:

1. A coated paper or paperboard structure comprising: a paper or paperboard substrate; and a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface, the basecoat comprising: water-soluble polymer binder; and pigment.

2. The coated paper or paperboard structure of Claim 1 wherein the paper or paperboard substrate is bleached.

3. The coated paper or paperboard structure of Claim 1 wherein the paper or paperboard substrate is unbleached.

4. The coated paper or paperboard structure of any preceding claim wherein the substrate includes one or more of corrugating medium, linerboard, solid bleached sulfate (SBS), folding boxboard (FBB), coated unbleached kraft (CUK), and recycled paper or paperboard.

5. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an uncoated basis weight of 20 pounds per 3000 ft2 or more.

6. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an uncoated basis weight in the range of 20 pounds per 3000 ft2 to about 400 pounds per 3000 ft2.

7. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an uncoated basis weight in the range of 100 pounds per 3000 ft2 to about 250 pounds per 3000 ft2.

8. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an uncoated basis weight in the range of 120 pounds per 3000 ft2 to about 140 pounds per 3000 ft2.

9. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an average caliper thickness of 0.002 inch or greater (2 point or greater).

10. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an average caliper thickness in the range of 0.002 inch to 0.035 inch (2 point to 35 point).

11. The coated paper or paperboard structure of any preceding claim wherein the paper or paperboard substrate has an average caliper thickness in the range of 0.008 inch to 0.026 inch (8 point to 26 point).

12. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder consists of one or more natural water-soluble polymers.

13. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes a protein.

14. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes an animal-based protein.

15. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes an animal -based protein in the form of one or more of keratin and collagen.

16. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes an animal-based protein in the form of gelatin.

17. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a plant-based protein.

18. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a plant-based protein derived from soy.

19. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes a carbohydrate.

20. The coated paper or paperboard structure of any preceding claim wherein the water- soluble polymer binder includes a polysaccharide.

21. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a carbohydrate in the form of cellulose derivative.

22. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch.

23. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch derived from one or more of corn and potatoes.

24. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural gum.

25. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural botanical gum.

26. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural botanical gum derived from the woody element of plants.

27. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural botanical gum derived from seed coatings.

28. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural botanical gum in the form of one or more of alginate, cellulose derivatives, carrageenan, guar gum and xanthan.

29. The coated paper or paperboard structure of any of Claims 1-13 wherein the water- soluble polymer binder includes a natural botanical gum in the form of carboxymethyl cellulose (CMC).

30. The coated paper or paperboard structure of any preceding claim wherein the pigment includes an inorganic pigment.

31. The coated paper or paperboard structure of any preceding claim wherein the pigment includes calcium carbonate.

32. The coated paper or paperboard structure of any preceding claim wherein the pigment includes ground calcium carbonate.

33. The coated paper or paperboard structure of any preceding claim wherein the pigment includes fine ground calcium carbonate, wherein more than 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

34. The coated paper or paperboard structure of any of Claims 1-32 wherein the pigment includes course ground calcium carbonate, wherein 45 to 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

35. The coated paper or paperboard structure of any of Claims 1-32 wherein the pigment includes extra course ground calcium carbonate, wherein less than 45 percent of the calcium carbonate particles are less than 2 microns in diameter.

36. The coated paper or paperboard structure of any preceding claim wherein the pigment includes calcium carbonate having a median particle diameter of 1 micron or more.

37. The coated paper or paperboard structure of any preceding claim wherein the pigment includes calcium carbonate having a median particle diameter of 1.5 micron or more.

38. The coated paper or paperboard structure of any preceding claim wherein the pigment includes calcium carbonate having a median particle diameter of 3 micron or more.

39. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a kaolin clay.

40. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay.

41. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having an aspect ratio in excess of 40:1.

42. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having an aspect ratio in excess of 50:1.

43. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having an aspect ratio in excess of 70: 1.

44. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having an aspect ratio in excess of 90: 1.

45. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having a median particle diameter of 4 microns or more.

46. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having a median particle diameter of 10 microns or more.

47. The coated paper or paperboard structure of any of Claims 1-30 wherein the pigment includes a platy clay having a median particle diameter of 13 microns or more.

48. The coated paper or paperboard structure of any preceding claim wherein the pigment includes a pigment blend of calcium carbonate and a platy clay.

49. The coated paper or paperboard structure of any preceding claim wherein the pigment includes a pigment blend of calcium carbonate and a platy clay, wherein the calcium carbonate comprises at least 10 percent by weight of the pigment blend and at most 85 percent by weight of the pigment blend.

50. The coated paper or paperboard structure of any preceding claim wherein a ratio of the water-soluble polymer binder to the pigment is less than 1 : 1 by weight.

51. The coated paper or paperboard structure of any preceding claim wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :2 to 1 :20 by weight.

52. The coated paper or paperboard structure of any preceding claim wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :3 to 1 :7 by weight.

53. The coated paper or paperboard structure of any preceding claim wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :4 to 1 :5 by weight.

54. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a crosslinker.

55. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises at least one of a glyoxal-based crosslinker and a zirconium-based crosslinker.

56. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a crosslinker in an amount of 1% to 10% by weight of the amount of water- soluble polymer binder.

57. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a crosslinker in an amount of 2% to 8% by weight of the amount of water- soluble polymer binder.

58. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a crosslinker in an amount of 3% to 6% by weight of the amount of water- soluble polymer binder.

59. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a humectant.

60. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a humectant in form of one or more of glycerin and sorbitol.

61. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a humectant in an amount of 1% to 30% by weight of the amount of water- soluble polymer binder.

62. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a humectant in an amount of 5% to 30% by weight of the amount of water- soluble polymer binder.

63. The coated paper or paperboard structure of any preceding claim wherein the basecoat further comprises a humectant in an amount of 5% to 15% by weight of the amount of water- soluble polymer binder.

64. The coated paper or paperboard structure of any of Claims 1-62 wherein the basecoat further comprises a humectant in an amount of 15% to 25% by weight of the amount of water- soluble polymer binder.

65. The coated paper or paperboard structure of any of Claims 1-62 wherein the basecoat further comprises a humectant in an amount of 25% to 30% by weight of the amount of water- soluble polymer binder.

66. The coated paper or paperboard structure of any preceding claim wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 4 to 12 pounds per 3000 square feet of the paper or paperboard substrate.

67. The coated paper or paperboard structure of any preceding claim wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 5 to 11 pounds per 3000 square feet of the paper or paperboard substrate.

68. The coated paper or paperboard structure of any preceding claim wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 6 to 10 pounds per 3000 square feet of the paper or paperboard substrate.

69. The coated paper or paperboard structure of any preceding claim wherein the basecoat is latex-free.

70. The coated paper or paperboard structure of any preceding claim wherein the as- basecoated paper or paperboard substrate has a PPS10S roughness of 7 m or less.

71. The coated paper or paperboard structure of any preceding claim wherein the as- basecoated paper or paperboard substrate has a PPS10S roughness of 6.5 m or less.

72. The coated paper or paperboard structure of any preceding claim wherein the as- basecoated paper or paperboard substrate has a PPS10S roughness of 6 m or less.

73. The coated paper or paperboard structure of any preceding claim wherein the as- basecoated paper or paperboard substrate has a PPS10S roughness of 5.5 m or less.

74. A coated paper or paperboard structure comprising: a paper or paperboard substrate; a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface; and a topcoat applied over the basecoat to yield a topcoat outer surface, wherein at least one of the basecoat and the topcoat comprises: water-soluble polymer binder; and pigment.

75. The coated paper or paperboard structure of Claim 74, wherein the paper or paperboard substrate is bleached.

76. The coated paper or paperboard structure of Claim 74, wherein the paper or paperboard substrate is unbleached.

77. The coated paper or paperboard structure of any of Claims 74-76, wherein the paper or paperboard substrate includes one or more of corrugating medium, linerboard, solid bleached sulfate (SBS), folding boxboard (FBB), coated unbleached kraft (CUK), and recycled paper or paperboard.

78. The coated paper or paperboard structure of any of Claims 74-77, wherein the paper or paperboard substrate has an uncoated basis weight of 20 pounds per 3000 ft2 or more.

79. The coated paper or paperboard structure of any of Claims 74-78, wherein the paper or paperboard substrate has an uncoated basis weight in the range of 20 pounds per 3000 ft2 to about 400 pounds per 3000 ft2.

80. The coated paper or paperboard structure of any of Claims 74-79, wherein the paper or paperboard substrate has an uncoated basis weight in the range of 100 pounds per 3000 ft2 to about 250 pounds per 3000 ft2.

81. The coated paper or paperboard structure of any of Claims 74-80, wherein the paper or paperboard substrate has an uncoated basis weight in the range of 120 pounds per 3000 ft2 to about 140 pounds per 3000 ft2.

82. The coated paper or paperboard structure of any of Claims 74-81, wherein the paper or paperboard substrate has an average caliper thickness of 0.002 inch or greater (2 point or greater).

83. The coated paper or paperboard structure of any of Claims 74-82, wherein the paper or paperboard substrate has an average caliper thickness in the range of 0.002 inch to 0.035 inch (2 point to 35 point).

84. The coated paper or paperboard structure of any of Claims 74-83, wherein the paper or paperboard substrate has an average caliper thickness in the range of 0.008 inch to 0.026 inch (8 point to 26 point).

85. The coated paper or paperboard structure of Claim 74 wherein the basecoat comprises: water-soluble polymer binder; and pigment.

86. The coated paper or paperboard structure of Claim 85 wherein the water-soluble polymer binder consists of one or more natural water-soluble polymers.

87. The coated paper or paperboard structure of Claim 85 or Claim 86 wherein the water- soluble polymer binder includes a protein.

88. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes an animal-based protein.

89. The coated paper or paperboard structure of any of Claims 85-88 wherein the water- soluble polymer binder includes an animal -based protein in the form of one or more of keratin and collagen.

90. The coated paper or paperboard structure of any of Claims 85-89 wherein the water- soluble polymer binder includes an animal-based protein in the form of gelatin.

91. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a plant-based protein.

92. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a plant-based protein derived from soy.

93. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a carbohydrate.

94. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a polysaccharide.

95. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a carbohydrate in the form of cellulose derivative.

96. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch.

97. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch derived from one or more of corn and potatoes.

98. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural gum.

99. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural botanical gum.

100. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural botanical gum derived from the woody element of plants.

101. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural botanical gum derived from seed coatings.

102. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural botanical gum in the form of one or more of alginate, cellulose derivatives, carrageenan, guar gum and xanthan.

103. The coated paper or paperboard structure of any of Claims 85-87 wherein the water- soluble polymer binder includes a natural botanical gum in the form of carboxymethyl cellulose (CMC).

104. The coated paper or paperboard structure of any of Claims 85-103 wherein the pigment includes an inorganic pigment.

105. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes calcium carbonate.

106. The coated paper or paperboard structure of any of Claims 85-105 wherein the pigment includes ground calcium carbonate.

107. The coated paper or paperboard structure of any of Claims 85-106 wherein the pigment includes fine ground calcium carbonate, wherein more than 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

108. The coated paper or paperboard structure of any of Claims 85-105 wherein the pigment includes course ground calcium carbonate, wherein 45 to 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

109. The coated paper or paperboard structure of any of Claims 85-105 wherein the pigment includes extra course ground calcium carbonate, wherein less than 45 percent of the calcium carbonate particles are less than 2 microns in diameter.

110. The coated paper or paperboard structure of any of Claims 85-109 wherein the pigment includes calcium carbonate having a median particle diameter of 1 micron or more.

111. The coated paper or paperboard structure of any of Claims 85-110 wherein the pigment includes calcium carbonate having a median particle diameter of 1.5 micron or more.

112. The coated paper or paperboard structure of any of Claims 85-111 wherein the pigment includes calcium carbonate having a median particle diameter of 3 micron or more.

113. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a kaolin clay.

114. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay.

115. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having an aspect ratio in excess of 40:1.

116. The coated paper or paperboard structure any of Claims 85-104 wherein the pigment includes a platy clay having an aspect ratio in excess of 50:1.

117. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having an aspect ratio in excess of 70: 1.

118. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having an aspect ratio in excess of 90: 1.

119. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having a median particle diameter of 4 microns or more.

120. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having a median particle diameter of 10 microns or more.

121. The coated paper or paperboard structure of any of Claims 85-104 wherein the pigment includes a platy clay having a median particle diameter of 13 microns or more.

122. The coated paper or paperboard structure of any of Claims 85-121 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay.

123. The coated paper or paperboard structure of any of Claims 85-122 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay, wherein the calcium carbonate comprises at least 10 percent by weight of the pigment blend and at most 85 percent by weight of the pigment blend.

124. The coated paper or paperboard structure of any of Claims 85-123 wherein a ratio of the water-soluble polymer binder to the pigment is less than 1 : 1 by weight.

125. The coated paper or paperboard structure of any of Claims 85-124 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :2 to 1 :20 by weight.

126. The coated paper or paperboard structure of any of Claims 85-125 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :3 to 1 :7 by weight.

127. The coated paper or paperboard structure of any of Claims 85-126 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :4 to 1 :5 by weight.

128. The coated paper or paperboard structure of any of Claims 85-127 wherein the basecoat further comprises a crosslinker.

129. The coated paper or paperboard structure of any of Claims 85-128 wherein the basecoat further comprises at least one of a glyoxal-based crosslinker and a zirconium-based crosslinker.

130. The coated paper or paperboard structure of any of Claims 85-129 wherein the basecoat further comprises a crosslinker in an amount of 1% to 10% by weight of the amount of water- soluble polymer binder.

131. The coated paper or paperboard structure of any of Claims 85-130 wherein the basecoat further comprises a crosslinker in an amount of 2% to 8% by weight of the amount of water- soluble polymer binder.

132. The coated paper or paperboard structure of any of Claims 85-131 wherein the basecoat further comprises a crosslinker in an amount of 3% to 6% by weight of the amount of water- soluble polymer binder.

133. The coated paper or paperboard structure of any of Claims 85-132 wherein the basecoat further comprises a humectant.

134. The coated paper or paperboard structure of any of Claims 85-133 wherein the basecoat further comprises a humectant in form of one or more of glycerin and sorbitol.

135. The coated paper or paperboard structure of any of Claims 85-134 wherein the basecoat further comprises a humectant in an amount of 1% to 30% by weight of the amount of water- soluble polymer binder.

136. The coated paper or paperboard structure of any of Claims 85-135 wherein the basecoat further comprises a humectant in an amount of 5% to 30% by weight of the amount of water- soluble polymer binder.

137. The coated paper or paperboard structure of any of Claims 85-136 wherein the basecoat further comprises a humectant in an amount of 5% to 15% by weight of the amount of water- soluble polymer binder.

138. The coated paper or paperboard structure of any of Claims 85-136 wherein the basecoat further comprises a humectant in an amount of 15% to 25% by weight of the amount of water- soluble polymer binder.

139. The coated paper or paperboard structure of any of Claims 85-136 wherein the basecoat further comprises a humectant in an amount of 25% to 30% by weight of the amount of water- soluble polymer binder.

140. The coated paper or paperboard structure of any of Claims 85-139 wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 4 to 12 pounds per 3000 square feet of the paper or paperboard substrate.

141. The coated paper or paperboard structure of any of Claims 85-140 wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 5 to 11 pounds per 3000 square feet of the paper or paperboard substrate.

142. The coated paper or paperboard structure of any of Claims 85-141 wherein the basecoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 6 to 10 pounds per 3000 square feet of the paper or paperboard substrate.

143. The coated paper or paperboard structure of any of Claims 85-142 wherein the basecoat is latex-free.

144. The coated paper or paperboard structure of any of Claims 85-143 wherein the basecoated paper or paperboard substrate has a PPS10S roughness of 7 m or less.

145. The coated paper or paperboard structure of any of Claims 85-144 wherein the basecoated paper or paperboard substrate has a PPS10S roughness of 6.5 m or less.

146. The coated paper or paperboard structure of any of Claims 85-145 wherein the basecoated paper or paperboard substrate has a PPS10S roughness of 6 m or less.

147. The coated paper or paperboard structure of any of Claims 85-146 wherein the basecoated paper or paperboard substrate has a PPS10S roughness of 5.5 m or less.

148. The coated paper or paperboard structure of Claim 74 wherein the topcoat comprises: water-soluble polymer binder; and pigment.

149. The coated paper or paperboard structure of Claim 148 wherein the water-soluble polymer binder consists of one or more natural water-soluble polymers.

150. The coated paper or paperboard structure of Claim 148 or Claim 149 wherein the water- soluble polymer binder includes a protein.

151. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes an animal-based protein.

152. The coated paper or paperboard structure of any of Claims 148-151 wherein the water- soluble polymer binder includes an animal -based protein in the form of one or more of keratin and collagen.

153. The coated paper or paperboard structure of any of Claims 148-152 wherein the water- soluble polymer binder includes an animal-based protein in the form of gelatin.

154. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a plant-based protein.

155. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a plant-based protein derived from soy.

156. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a carbohydrate.

157. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a polysaccharide.

158. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a carbohydrate in the form of cellulose derivative.

159. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch.

160. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch derived from one or more of corn and potatoes.

161. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural gum.

162. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural botanical gum.

163. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural botanical gum derived from the woody element of plants.

164. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural botanical gum derived from seed coatings.

165. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural botanical gum in the form of one or more of alginate, cellulose derivatives, carrageenan, guar gum and xanthan.

166. The coated paper or paperboard structure of any of Claims 148-150 wherein the water- soluble polymer binder includes a natural botanical gum in the form of carboxymethyl cellulose (CMC).

167. The coated paper or paperboard structure of any of Claims 148-166 wherein the pigment includes an inorganic pigment.

168. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes calcium carbonate.

169. The coated paper or paperboard structure of any of Claims 148-168 wherein the pigment includes ground calcium carbonate.

170. The coated paper or paperboard structure of any of Claims 148-169 wherein the pigment includes fine ground calcium carbonate, wherein more than 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

171. The coated paper or paperboard structure of any of Claims 148-168 wherein the pigment includes course ground calcium carbonate, wherein 45 to 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

172. The coated paper or paperboard structure of any of Claims 148-168 wherein the pigment includes extra course ground calcium carbonate, wherein less than 45 percent of the calcium carbonate particles are less than 2 microns in diameter.

173. The coated paper or paperboard structure of any of Claims 148-172 wherein the pigment includes calcium carbonate having a median particle diameter of 1 micron or more.

174. The coated paper or paperboard structure of any of Claims 148-173 wherein the pigment includes calcium carbonate having a median particle diameter of 1.5 micron or more.

175. The coated paper or paperboard structure of any of Claims 148-174 wherein the pigment includes calcium carbonate having a median particle diameter of 3 micron or more.

176. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a kaolin clay.

177. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay.

178. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having an aspect ratio in excess of 40:1.

179. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having an aspect ratio in excess of 50:1.

180. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having an aspect ratio in excess of 70: 1.

181. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having an aspect ratio in excess of 90: 1.

182. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having a median particle diameter of 4 microns or more.

183. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having a median particle diameter of 10 microns or more.

184. The coated paper or paperboard structure of any of Claims 148-167 wherein the pigment includes a platy clay having a median particle diameter of 13 microns or more.

185. The coated paper or paperboard structure of any of Claims 148-184 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay.

186. The coated paper or paperboard structure of any of Claims 148-185 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay, wherein the calcium carbonate comprises at least 10 percent by weight of the pigment blend and at most 85 percent by weight of the pigment blend.

187. The coated paper or paperboard structure of any of Claims 148-186 wherein a ratio of the water-soluble polymer binder to the pigment is less than 1 : 1 by weight.

188. The coated paper or paperboard structure of any of Claims 148-187 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :2 to 1 :40 by weight.

189. The coated paper or paperboard structure of any of Claims 148-188 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :3 to 1 :20 by weight.

190. The coated paper or paperboard structure of any of Claims 148-189 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :7 to 1 : 10 by weight.

191. The coated paper or paperboard structure of any of Claims 148-190 wherein the topcoat further comprises a crosslinker.

192. The coated paper or paperboard structure of any of Claims 148-191 wherein the topcoat further comprises at least one of a glyoxal-based crosslinker and a zirconium-based crosslinker.

193. The coated paper or paperboard structure of any of Claims 148-192 wherein the topcoat further comprises a crosslinker in an amount of 1% to 10% by weight of the amount of water- soluble polymer binder.

194. The coated paper or paperboard structure of any of Claims 148-193 wherein the topcoat further comprises a crosslinker in an amount of 4% to 8% by weight of the amount of water- soluble polymer binder.

195. The coated paper or paperboard structure of any of Claims 148-194 wherein the topcoat further comprises a crosslinker in an amount of 3% to 6% by weight of the amount of water- soluble polymer binder.

196. The coated paper or paperboard structure of any of Claims 148-195 wherein the topcoat further comprises a humectant.

197. The coated paper or paperboard structure of any of Claims 148-196 wherein the topcoat further comprises a humectant in form of one or more of glycerin and sorbitol.

198. The coated paper or paperboard structure of any of Claims 148-197 wherein the topcoat further comprises a humectant in an amount of 1% to 30% by weight of the amount of water- soluble polymer binder.

199. The coated paper or paperboard structure of any of Claims 148-198 wherein the topcoat further comprises a humectant in an amount of 5% to 30% by weight of the amount of water- soluble polymer binder.

200. The coated paper or paperboard structure of any of Claims 148-199 wherein the topcoat further comprises a humectant in an amount of 5% to 15% by weight of the amount of water- soluble polymer binder.

201. The coated paper or paperboard structure of any of Claims 148-199 wherein the topcoat further comprises a humectant in an amount of 15% to 25% by weight of the amount of water- soluble polymer binder.

202. The coated paper or paperboard structure of any of Claims 148-199 wherein the topcoat further comprises a humectant in an amount of 25% to 30% by weight of the amount of water- soluble polymer binder.

203. The coated paper or paperboard structure of any of Claims 148-202 wherein the topcoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 3 to 12 pounds per 3000 square feet of the paper or paperboard substrate.

204. The coated paper or paperboard structure of any of Claims 148-203 wherein the topcoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 4 to 11 pounds per 3000 square feet of the paper or paperboard substrate.

205. The coated paper or paperboard structure of any of Claims 148-204 wherein the topcoat is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 5 to 10 pounds per 3000 square feet of the paper or paperboard substrate.

206. The coated paper or paperboard structure of any of Claims 148-205 wherein the topcoat is latex-free.

207. The coated paper or paperboard structure of any of Claims 148-206 wherein the topcoated paper or paperboard substrate has a PPS10S roughness of 2.6 m or less after calendering.

208. The coated paper or paperboard structure of any of Claims 148-207 wherein the topcoated paper or paperboard substrate has a PPS10S roughness of 2.3 m or less after calendering.

209. The coated paper or paperboard structure of any of Claims 148-208 wherein the topcoated paper or paperboard substrate has a PPS10S roughness of 2.1 m or less after calendering.

210. The coated paper or paperboard structure of any of Claims 148-209 wherein the topcoated paper or paperboard substrate has a PPS10S roughness of 1.9 m or less after calendering.

211. The coated paper or paperboard structure of any of Claims 148-210 wherein the topcoated paper or paperboard substrate has an ink holdout after two minutes of less than 30% decrease in brightness.

212. The coated paper or paperboard structure of any of Claims 148-211 wherein the topcoated paper or paperboard substrate has an ink holdout after two minutes of less than 25% decrease in brightness.

213. The coated paper or paperboard structure of any of Claims 148-212 wherein the topcoated paper or paperboard substrate has an ink holdout after two minutes of less than 20% decrease in brightness.

214. The coated paper or paperboard structure of any of Claims 148-213 wherein the topcoated paper or paperboard substrate has an ink holdout after two minutes of less than 15% decrease in brightness.

215. A coated paper or paperboard structure comprising: a paper or paperboard substrate; and a coating applied to the paper or paperboard substrate to yield a coating outer surface, the coating comprising: water-soluble polymer binder; and pigment.

216. The coated paper or paperboard structure of Claim 215 wherein the water-soluble polymer binder consists of one or more natural water-soluble polymers.

217. The coated paper or paperboard structure of Claim 215 or Claim 216 wherein the water- soluble polymer binder includes a protein.

218. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes an animal-based protein.

219. The coated paper or paperboard structure of any of Claims 215-218 wherein the water- soluble polymer binder includes an animal -based protein in the form of one or more of keratin and collagen.

220. The coated paper or paperboard structure of any of Claims 215-219 wherein the water- soluble polymer binder includes an animal-based protein in the form of gelatin.

221. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a plant-based protein.

222. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a plant-based protein derived from soy.

223. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a carbohydrate.

224. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a polysaccharide.

225. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a carbohydrate in the form of cellulose derivative.

226. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch.

227. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a carbohydrate in the form of starch derived from one or more of corn and potatoes.

228. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural gum.

229. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural botanical gum.

230. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural botanical gum derived from the woody element of plants.

231. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural botanical gum derived from seed coatings.

232. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural botanical gum in the form of one or more of alginate, cellulose derivatives, carrageenan, guar gum and xanthan.

233. The coated paper or paperboard structure of any of Claims 215-217 wherein the water- soluble polymer binder includes a natural botanical gum in the form of carboxymethyl cellulose (CMC).

234. The coated paper or paperboard structure of any of Claims 215-233 wherein the pigment includes an inorganic pigment.

235. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes calcium carbonate.

236. The coated paper or paperboard structure of any of Claims 215-235 wherein the pigment includes ground calcium carbonate.

237. The coated paper or paperboard structure of any of Claims 215-236 wherein the pigment includes fine ground calcium carbonate, wherein more than 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

238. The coated paper or paperboard structure of any of Claims 215-236 wherein the pigment includes course ground calcium carbonate, wherein 45 to 75 percent of the calcium carbonate particles are less than 2 microns in diameter.

239. The coated paper or paperboard structure of any of Claims 215-236 wherein the pigment includes extra course ground calcium carbonate, wherein less than 45 percent of the calcium carbonate particles are less than 2 microns in diameter.

240. The coated paper or paperboard structure of any of Claims 215-239 wherein the pigment includes calcium carbonate having a median particle diameter of 1 micron or more.

241. The coated paper or paperboard structure of any of Claims 215-240 wherein the pigment includes calcium carbonate having a median particle diameter of 1.5 micron or more.

242. The coated paper or paperboard structure of any of Claims 215-241 wherein the pigment includes calcium carbonate having a median particle diameter of 3 micron or more.

243. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a kaolin clay.

244. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay.

245. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having an aspect ratio in excess of 40:1.

246. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having an aspect ratio in excess of 50:1.

247. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having an aspect ratio in excess of 70: 1.

248. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having an aspect ratio in excess of 90: 1.

249. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having a median particle diameter of 4 microns or more.

250. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having a median particle diameter of 10 microns or more.

251. The coated paper or paperboard structure of any of Claims 215-234 wherein the pigment includes a platy clay having a median particle diameter of 13 microns or more.

252. The coated paper or paperboard structure of any of Claims 215-251 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay.

253. The coated paper or paperboard structure of any of Claims 215-252 wherein the pigment includes a pigment blend of calcium carbonate and a platy clay, wherein the calcium carbonate comprises at least 10 percent by weight of the pigment blend and at most 85 percent by weight of the pigment blend.

254. The coated paper or paperboard structure of any of Claims 215-253 wherein a ratio of the water-soluble polymer binder to the pigment is less than 1 : 1 by weight.

255. The coated paper or paperboard structure of any of Claims 215-254 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :2 to 1 :40 by weight.

256. The coated paper or paperboard structure of any of Claims 215-255 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :3 to 1 :20 by weight.

257. The coated paper or paperboard structure of any of Claims 215-256 wherein a ratio of the water-soluble polymer binder to the pigment is in a range of 1 :4 to 1 : 10 by weight.

258. The coated paper or paperboard structure of any of Claims 215-257 wherein the coating further comprises a crosslinker.

259. The coated paper or paperboard structure of any of Claims 215-258 wherein the coating further comprises at least one of a glyoxal-based crosslinker and a zirconium-based crosslinker.

260. The coated paper or paperboard structure of any of Claims 215-259 wherein the coating further comprises a crosslinker in an amount of 1% to 10% by weight of the amount of water- soluble polymer binder.

261. The coated paper or paperboard structure of any of Claims 215-260 wherein the coating further comprises a crosslinker in an amount of 2% to 8% by weight of the amount of water- soluble polymer binder.

262. The coated paper or paperboard structure of any of Claims 215-261 wherein the coating further comprises a crosslinker in an amount of 3% to 6% by weight of the amount of water- soluble polymer binder.

263. The coated paper or paperboard structure of any of Claims 215-262 wherein the coating further comprises a humectant.

264. The coated paper or paperboard structure of any of Claims 215-263 wherein the coating further comprises a humectant in form of one or more of glycerin and sorbitol.

265. The coated paper or paperboard structure of any of Claims 215-264 wherein the coating further comprises a humectant in an amount of 1% to 30% by weight of the amount of water- soluble polymer binder.

266. The coated paper or paperboard structure of any of Claims 215-265 wherein the coating further comprises a humectant in an amount of 5% to 30% by weight of the amount of water- soluble polymer binder.

267. The coated paper or paperboard structure of any of Claims 215-266 wherein the coating further comprises a humectant in an amount of 5% to 15% by weight of the amount of water- soluble polymer binder.

268. The coated paper or paperboard structure of any of Claims 215-266 wherein the coating further comprises a humectant in an amount of 15% to 25% by weight of the amount of water- soluble polymer binder.

269. The coated paper or paperboard structure of any of Claims 215-266 wherein the coating further comprises a humectant in an amount of 25% to 30% by weight of the amount of water- soluble polymer binder.

270. The coated paper or paperboard structure of any of Claims 215-269 wherein the coating is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 3 to 12 pounds per 3000 square feet of the paper or paperboard substrate.

271. The coated paper or paperboard structure of any of Claims 215-270 wherein the coating is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 4 to 11 pounds per 3000 square feet of the paper or paperboard substrate.

272. The coated paper or paperboard structure of any of Claims 215-271 wherein the coating is applied to the paper or paperboard substrate at a coat weight, per side, in a range of 5 to 10 pounds per 3000 square feet of the paper or paperboard substrate.

273. The coated paper or paperboard structure of any of Claims 215-272 wherein the coating is latex-free.

274. The coated paper or paperboard structure of any of Claims 215-273 wherein the coated paper or paperboard substrate has a PPS10S roughness of 3.5 m or less after calendering.

275. The coated paper or paperboard structure of any of Claims 215-274 wherein the coated paper or paperboard substrate has a PPS10S roughness of 3.0 m or less after calendering.

276. The coated paper or paperboard structure of any of Claims 215-275 wherein the coated paper or paperboard substrate has a PPS10S roughness of 2.6 m or less after calendering.

277. The coated paper or paperboard structure of any of Claims 215-276 wherein the coated paper or paperboard substrate has a PPS10S roughness of 2.3 m or less after calendering.

278. The coated paper or paperboard structure of any of Claims 215-277 wherein the coated paper or paperboard substrate has a PPS10S roughness of 2.1 m or less after calendering.

279. The coated paper or paperboard structure of any of Claims 215-278 wherein the coated paper or paperboard substrate has a PPS10S roughness of 1.9 m or less after calendering.

280. The coated paper or paperboard structure of any of Claims 215-279 wherein the coated paper or paperboard substrate has an ink holdout after two minutes of less than 30% decrease in brightness.

281. The coated paper or paperboard structure of any of Claims 215-280 wherein the coated paper or paperboard substrate has an ink holdout after two minutes of less than 25% decrease in brightness.

282. The coated paper or paperboard structure of any of Claims 215-281 wherein the coated paper or paperboard substrate has an ink holdout after two minutes of less than 20% decrease in brightness.

283. The coated paper or paperboard structure of any of Claims 215-282 wherein the coated paper or paperboard substrate has an ink holdout after two minutes of less than 15% decrease in brightness.

Description:
COATED PAPER AND PAPERBOARD STRUCTURE S

PRIORITY

[0001] The present application claims priority from U.S. Ser. No. 62/949,012 filed on December 17, 2019, the entire contents of which are incorporated herein by reference.

FIELD

[0002] The present application relates to the field of coated paper and coated paperboard structures.

BACKGROUND

[0003] Paper and paperboard substrates can be coated with one or more layers including latex binder and pigment. Compostability of such coated paper and paperboard substrates is limited by the presence of the latex binder. There is a need for paper and paperboard substrates that are more compostable and bio-based.

[0004] Accordingly, those skilled in the art continue with research and development in the field of coated paper and coated paperboard structures.

SUMMARY

[0005] In one embodiment, a coated paper or paperboard structure includes a paper or paperboard substrate and a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface. The basecoat includes a water-soluble polymer binder and pigment.

[0006] In another embodiment, a coated paper or paperboard structure includes a paper or paperboard substrate, a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface, and a topcoat applied over the basecoat to yield a topcoat outer surface. At least one of the basecoat and the topcoat includes a water-soluble polymer binder and a pigment. [0007] In yet another embodiment, a coated paper or paperboard structure includes a paper or paperboard substrate and a coating applied to the paper or paperboard substrate to yield a coating outer surface. The coating includes a water-soluble polymer binder and a pigment.

[0008] Other embodiments of the disclosed coated paper and coated paperboard structures will become apparent from the following detailed description, the accompanying drawings and the appended Claims.

BRIEF DE S CRIPTION OF THE DRAWINGS

[0009] Fig. l is a cross sectional view of a coated paper or paperboard structure of the present description including a paper or paperboard substrate and a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface.

[0010] Fig. 2 is a cross sectional view of a coated paper or paperboard structure of the present description including a paper or paperboard substrate, a basecoat applied to the paper or paperboard substrate to yield a basecoat outer surface, and a topcoat applied over the basecoat to yield a topcoat outer surface.

[0011] Fig. 3 is a cross sectional view of a coated paper or paperboard structure of the present description including a paper or paperboard substrate and a coating applied to the paper or paperboard substrate to yield a coating outer surface.

[0012] Fig. 4 is a plot of roughness of basecoated-only samples over a range of basecoat weights.

[0013] Fig. 5 is another plot of roughness of basecoated-only samples over a range of basecoat weights.

[0014] Fig. 6 is another plot of roughness of basecoated-only samples over a range of basecoat weights.

[0015] Fig. 7 is a plot of roughness after calendering of basecoated and topcoated samples over a range of basecoat weights. [0016] Fig. 8 is another plot of roughness after calendering of basecoated and topcoated samples over a range of basecoat weights.

[0017] Fig. 9 is another plot of roughness after calendering of basecoated and topcoated samples over a range of basecoat weights.

DETAILED DE S CRIPTION

[0018] Fig. 1 is a cross sectional view of a coated paper or paperboard structure 100 according to a first embodiment of the present description. As shown in Fig. 1, the coated paper or paperboard structure 100 includes a paper or paperboard substrate 110 and a basecoat 120 applied to a surface 112 the paper or paperboard substrate 110 to yield a basecoat outer surface 122. According to the present description, the basecoat 120 includes a water-soluble polymer binder and a pigment.

[0019] The basecoat 120 is a coating intended to have at least one or more coatings applied over it in a final coated paper or paperboard product. The basecoat 120 is different from a topcoat and different from a coating of a single-coated product because the basecoat 120 is applied as an intermediate stage in the paperboard coating process. A basecoat 120 is not processed the same as a topcoat or a single-coated product. The basecoat 120 has one or more coatings applied over it in a final coated paper or paperboard product, whereas the topcoat or the single-coated product are subjected to post processing (e.g., calendering, printing, and converting).

[0020] The basecoat 120 may be applied to the paper or paperboard substrate 110 in any amount suitable for the intended use of the coated paper or paperboard structure 100. In an example, the basecoat 120 may be applied to the paper or paperboard substrate 110 at a coat weight, per side, in a range of 4 to 12 pounds per 3000 square feet of the paper or paperboard substrate 110. In another example, the basecoat 120 may be applied to the paper or paperboard substrate 110 at a coat weight, per side, in a range of 5 to 11 pounds per 3000 square feet of the paper or paperboard substrate 110. In yet another example, the basecoat 120 may be applied to the paper or paperboard substrate 110 at a coat weight, per side, in a range of 6 to 10 pounds per 3000 square feet of the paper or paperboard substrate 110. [0021] In an aspect, the as-basecoated paper or paperboard substrate 110, i.e. the paper or paperboard substrate 110 upon being coated with the basecoat 120, may have a PPS10S roughness (Parker Print Surf roughness measured using 10 psi pressure with a soft backing) of 7 m or less. In another aspect, the as-basecoated paper or paperboard substrate 110 may have a PPS10S roughness of 6.5 m or less. In yet another aspect, the as-basecoated paper or paperboard substrate 110 may have a PPS10S roughness of 6 m or less. In yet another aspect, the as- basecoated paper or paperboard substrate 110 may have a PPS10S roughness of 5.5 m or less. Thus, the as-basecoated paper or paperboard substrate 110 of the present description can enable modern sheet smoothness without necessitating any latex binder.

[0022] Fig. 2 is a cross sectional view of a coated paper or paperboard structure 200 according to a second embodiment of the present description. As shown in Fig. 2, the coated paper or paperboard structure 200 includes a paper or paperboard substrate 210, a basecoat 220 applied to the paper or paperboard substrate 210 to yield a basecoat outer surface 222, and a topcoat 230 applied over the basecoat 220 to yield a topcoat outer surface 232.

[0023] In one aspect, as shown, the topcoat 230 may be applied directed on the basecoat outer surface 222 without any intermediate layers. In another aspect, one or more intermediate layers may be included between the basecoat 220 and the topcoat 230. In an example, a second basecoat may be included between the basecoat 220 and the topcoat 230. In another example, a barrier layer may be included between the basecoat 220 and the topcoat 230.

[0024] According to the present description, at least one of the basecoat 220 and the topcoat 230 includes a water-soluble polymer binder and a pigment. In one aspect, the basecoat 220 includes a water-soluble polymer binder and a pigment. In another aspect, the topcoat 230 includes a water-soluble polymer binder and a pigment. In yet another aspect, the basecoat 220 and the topcoat 230 include a water-soluble polymer binder and a pigment. The basecoat 220 and the topcoat 230 may have the same composition or may have different compositions.

[0025] The basecoat 220 may be applied to the paper or paperboard substrate 210 in any amount suitable for the intended use of the coated paper or paperboard structure 200. In an example, the basecoat 220 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 4 to 12 pounds per 3000 square feet of the paper or paperboard substrate 210. In another example, the basecoat 220 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 5 to 11 pounds per 3000 square feet of the paper or paperboard substrate 210. In yet another example, the basecoat 220 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 6 to 10 pounds per 3000 square feet of the paper or paperboard substrate 210.

[0026] In an aspect, the as-basecoated paper or paperboard substrate 210 may have a PPS10S roughness of 7 m or less. In another aspect, the as-basecoated paper or paperboard substrate 210 may have a PPS10S roughness of 6.5 m or less. In yet another aspect, the as-basecoated paper or paperboard substrate 210 may have a PPS10S roughness of 6 m or less. In yet another aspect, the as-basecoated paper or paperboard substrate 210 may have a PPS10S roughness of 5.5 m or less. Thus, the as-basecoated paper or paperboard substrate 210 of the present description can enable modern sheet smoothness without necessitating any latex binder.

[0027] The topcoat 230 may be applied to the paper or paperboard substrate 210 in any amount suitable for the intended use of the coated paper or paperboard structure 200. In an example, the topcoat 230 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 3 to 12 pounds per 3000 square feet of the paper or paperboard substrate 210. In another example, the topcoat 230 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 4 to 11 pounds per 3000 square feet of the paper or paperboard substrate 210. In yet another example, the topcoat 230 may be applied to the paper or paperboard substrate 210 at a coat weight, per side, in a range of 5 to 10 pounds per 3000 square feet of the paper or paperboard substrate 210.

[0028] In an aspect, the topcoated paper or paperboard substrate 210 may have a PPS10S roughness of 2.6 m or less after calendering. In another aspect, the topcoated paper or paperboard substrate 210 may have a PPS10S roughness of 2.3 m or less after calendering. In yet another aspect, the topcoated paper or paperboard substrate 210 may have a PPS10S roughness of 2.1 m or less after calendering. In yet another aspect, the topcoated paper or paperboard substrate 210 may have a PPS10S roughness of 1.9 m or less after calendering. Thus, the topcoated paper or paperboard substrate 210 of the present description can enable modern sheet smoothness without necessitating any latex binder. [0029] In an aspect, the topcoated paper or paperboard substrate 210 may have an ink holdout after two minutes of less than 30% decrease in brightness. In another aspect, the topcoated paper or paperboard substrate 210 may have an ink holdout after two minutes of less than 25% decrease in brightness. In yet another aspect, the topcoated paper or paperboard substrate 210 may have an ink holdout after two minutes of less than 20% decrease in brightness. In yet another aspect, the topcoated paper or paperboard substrate 210 may have an ink holdout after two minutes of less than 15% decrease in brightness. Thus, the topcoated paper or paperboard substrate 210 of the present description can enable good smoothness and acceptable printing performance without necessitating any latex binder.

[0030] Fig. 3 is a cross sectional view of a coated paper or paperboard structure 300 according to a third embodiment of the present description. As shown in Fig. 3, the coated paper or paperboard structure 300 includes a paper or paperboard substrate 310 and a coating 340 applied to the paper or paperboard substrate 310 to yield a coating outer surface 342. According to the present description, the coating 340 includes a water-soluble polymer binder and a pigment.

[0031] The coating 340 is intended to yield a coating outer surface 342 of the coated paper or paperboard structure 300. The coating 340 is different from a basecoat. A basecoat is not processed the same as a single-coated product. A basecoat has one or more coatings applied over it in a final coated paper or paperboard product, whereas the single-coated product are subjected to post processing (e.g., calendering, printing, and converting).

[0032] The coating 340 may be applied to the paper or paperboard substrate 310 in any amount suitable for the intended use of the coated paper or paperboard structure 300. In an example, the coating 340 may be applied to the paper or paperboard substrate 310 at a coat weight, per side, in a range of 3 to 12 pounds per 3000 square feet of the paper or paperboard substrate 310. In another example, the coating 340 may be applied to the paper or paperboard substrate 310 at a coat weight, per side, in a range of 4 to 11 pounds per 3000 square feet of the paper or paperboard substrate 310. In yet another example, the coating 340 may be applied to the paper or paperboard substrate 310 at a coat weight, per side, in a range of 5 to 10 pounds per 3000 square feet of the paper or paperboard substrate 310. [0033] In an aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 3.5 m or less after calendering. In another aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 3.0 m or less after calendering. In yet another aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 2.6 m or less after calendering. In yet another aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 2.3 m or less after calendering. In yet another aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 2.1 m or less after calendering. In yet another aspect, the coated paper or paperboard substrate 310 may have a PPS10S roughness of 1.9 m or less after calendering. Thus, the coated paper or paperboard substrate 310 of the present description can enable modern sheet smoothness without necessitating any latex binder.

[0034] In an aspect, the coated paper or paperboard substrate 310 may have an ink holdout after two minutes of less than 30% decrease in brightness. In another aspect, the coated paper or paperboard substrate 310 may have an ink holdout after two minutes of less than 25% decrease in brightness. In yet another aspect, the coated paper or paperboard substrate 310 may have an ink holdout after two minutes of less than 20% decrease in brightness. In yet another aspect, the coated paper or paperboard substrate 310 may have an ink holdout after two minutes of less than 15% decrease in brightness. Thus, the coated paper or paperboard substrate 310 of the present description can enable good smoothness and acceptable printing performance without necessitating any latex binder.

[0035] The coated paper or paperboard structures 100, 200, and 300 may include one or more of the following additional features.

[0036] The paper or paperboard substrates of the coated paper or paperboard structures 100, 200, and 300 may be selected from any paper or paperboard substrate suitable for applying a coating thereon.

[0037] The paper or paperboard substrate may be bleached or unbleached.

[0038] The paper or paperboard substrate may include any grade of paper or paperboard suitable for applying a coating thereon. The paper or paperboard substrate may include, for example, corrugating medium, linerboard, solid bleached sulfate (SBS), folding boxboard (FBB), coated unbleached kraft (CUK), and recycled paper or paperboard.

[0039] The paper or paperboard substrate may include any uncoated basis weight suitable for applying a coating thereon. The paper or paperboard substrate may have, for example, an uncoated basis weight of 20 pounds per 3000 ft 2 or more. For example, the paper or paperboard substrate may have an uncoated basis weight in the range of 20 pounds per 3000 ft 2 to about 400 pounds per 3000 ft 2 . In a specific example, the paper or paperboard substrate may have an uncoated basis weight in the range of 20 pounds per 3000 ft 2 to about 60 pounds per 3000 ft 2 . In another specific example, the paper or paperboard substrate may have an uncoated basis weight in the range of 60 pounds per 3000 ft 2 to about 120 pounds per 3000 ft 2 . In another specific example, the paper or paperboard substrate may have an uncoated basis weight in the range of 100 pounds per 3000 ft 2 to about 250 pounds per 3000 ft 2 . In another specific example, the paper or paperboard substrate may have an uncoated basis weight in the range of 120 pounds per 3000 ft 2 to about 140 pounds per 3000 ft 2 .

[0040] The paper or paperboard substrate may include any thickness suitable for applying a coating thereon. The paper or paperboard substrate may have, for example, an average caliper thickness of 0.002 inch or greater (2 point or greater). In a specific example, the paper or paperboard substrate may have an average caliper thickness in the range of 0.002 inch to 0.035 inch (2 point to 35 point). In another specific example, the paper or paperboard substrate may have an average caliper thickness in the range of 0.008 inch to 0.026 inch (8 point to 26 point).

[0041] In an aspect, the basecoat 120, the basecoat 220, the topcoat 230, and the coating 340 may optionally include one or more additional soluble binders with the water-soluble polymer binder. In another aspect, the basecoat 120, the basecoat 220, the topcoat 230, and the coating 340 may include no binders other than the water-soluble polymer binder. In a particular aspect, the basecoat 120, basecoat 220, topcoat 230, or coating 340 may be latex-free.

[0042] The water-soluble polymer binder may consist of a single water-soluble polymer binder composition or may include a blend of water-soluble polymer binder compositions. [0043] In an aspect, the water-soluble polymer binder include one or more natural water- soluble polymer binders, which are derived from a natural source. In another aspect, the water- soluble polymer binder consist of the one or more natural water-soluble polymer binders.

[0044] An advantage of the coated paper or paperboard structure with no latex binder using all natural binders may be highly compostable.

[0045] In an example, the water-soluble polymer binder may include a protein. The protein may be animal-based protein or a plant-based protein. The animal-based protein may be in the form of, for example, keratin and collagen. The animal-based protein may be in the form of, for example, gelatin. The plant-based protein may be derived from, for example, soy.

[0046] In an example, the water-soluble polymer binder may include a carbohydrate. The carbohydrate may be in the form of cellulose derivative. The carbohydrate may be in the form of starch. The starch may be derived from, for example, corn or potatoes.

[0047] In an example, the water-soluble polymer binder may include a natural gum. The natural gum may include, for example, a natural botanical gum. The natural botanical gum may include, for example, a natural botanical gum derived from the woody element of plants. In another example, the natural botanical gum may include a natural botanical gum derived from seed coatings. In a specific example, the water-soluble polymer binder may include a natural botanical gum in the form of one or more of alginate, cellulose derivatives, carrageenan, guar gum and xanthan. In another specific example, the water-soluble polymer binder may include a natural botanical gum in the form of carboxymethyl cellulose (CMC).

[0048] The pigment of the basecoat 120, the basecoat 220, the topcoat 230, and/or or the coating 340 may include one or more of the following features.

[0049] The pigment may have a single composition or may be a blend of pigment.

[0050] In an aspect, the pigment may include an inorganic pigment.

[0051] In an aspect, the pigment may include calcium carbonate. The calcium carbonate may include, for example, ground calcium carbonate. The ground calcium carbonate may be, for example, fine ground calcium carbonate, wherein more than 75 percent of the calcium carbonate particles are less than 2 microns in diameter. The ground calcium carbonate may be, for example, course ground calcium carbonate, wherein 45 to 75 percent of the calcium carbonate particles are less than 2 microns in diameter. The ground calcium carbonate may be, for example, extra course ground calcium carbonate, wherein less than 45 percent of the calcium carbonate particles are less than 2 microns in diameter.

[0052] In an aspect, the pigment may include calcium carbonate having a median particle diameter of 1 micron or more. In another aspect, the pigment may include calcium carbonate having a median particle diameter of 1.5 micron or more. In yet another aspect, the pigment may include calcium carbonate having a median particle diameter of 3 micron or more. The median particle diameter is the median particle diameter as measured by a sedimentation-based method, i.e. the SediGraph by Micromeritics.

[0053] The pigment may include kaolin clay. The kaolin clay may include a platy clay.

[0054] In an aspect, the platy clay may have an aspect ratio in excess of 40: 1. In another aspect, the platy clay may have an aspect ratio in excess of 50: 1. In yet another aspect, the platy clay may have an aspect ratio in excess of 70: 1. In yet another aspect, the platy clay may have an aspect ratio in excess of 90: 1.

[0055] In an aspect, the platy clay may have a median particle diameter of 4 microns or more.

In another aspect, the platy clay may have a median particle diameter of 10 microns or more. In yet another aspect, the platy clay may have a median particle diameter of 13 microns or more.

[0056] The pigment may include a pigment blend. The pigment blend may include, for example, a blend of calcium carbonate and a platy clay. The amounts of calcium carbonate and platy clay are not limited. In an example, the calcium carbonate may be included in amount of between 10 percent by weight of the pigment blend and 85 percent by weight of the pigment blend.

[0057] The amounts of water-soluble polymer binder and pigment in the basecoat 120, basecoat 220, topcoat 230, or coating 340 are not limited. In an example, a ratio of the water- soluble polymer binder to the pigment may be less than 1 : 1 by weight. In another example, a ratio of the water-soluble polymer binder to the pigment may be in a range of 1 :2 to 1 :20 by weight. In yet another example, a ratio of the water-soluble polymer binder to the pigment may be in a range of 1 :3 to 1 :7 by weight. In yet another example, a ratio of the water-soluble polymer binder to the pigment may be in a range of 1 :4 to 1 :5 by weight.

[0058] The basecoat 120, basecoat 220, topcoat 230, or coating 340 may include additives other than the water-soluble polymer binder and the pigment to improve or enhance their performance.

[0059] In an aspect, the basecoat 120, basecoat 220, topcoat 230, or coating 340 may include a crosslinker (also referred to as insolubilizer). The crosslinker causes the water-soluble polymer binder molecules to bond with each other upon drying which gives the respective coatings greater water resistance.

[0060] In an example, the crosslinker may include a glyoxal-based crosslinker. In another example, the crosslinker may include a zirconium-based crosslinker. In yet another example, the crosslinker may include a glyoxal-based crosslinker and a zirconium-based crosslinker. The amount of the crosslinker is not limited. In an example, the crosslinker may be included in an amount of 1% to 20% by weight of the amount of water-soluble polymer binder. In another example, the crosslinker may be included in an amount of 1% to 10% by weight of the amount of water-soluble polymer binder. In another example, the crosslinker may be included in an amount of 4% to 8% by weight of the amount of water-soluble polymer binder. In yet another example, the crosslinker may be included in an amount of 3% to 6% by weight of the amount of water- soluble polymer binder.

[0061] In another aspect, the basecoat 120, basecoat 220, topcoat 230, or coating 340 may include a humectant (water loving material) that functions as a plasticizer for the water-soluble polymer binder by retaining water in the dried coating.

[0062] In an example, the humectant may include a humectant in form of glycerin. In another example, the humectant may include a humectant in form of sorbitol. In yet another example, the humectant may include a humectant in form of glycerin and sorbitol. The amount of the humectant is not limited. In an example, the humectant may be included in an amount of 1% to 30% by weight of the amount of water-soluble polymer binder. In another example, the humectant may be included in an amount of 5% to 30% by weight of the amount of water- soluble polymer binder. In yet another example, the humectant may be included in an amount of 5% to 15% by weight of the amount of water-soluble polymer binder. In yet another example, the humectant may be included in an amount of 15% to 25% by weight of the amount of water- soluble polymer binder. In yet another example, the humectant may be included in an amount of 25% to 30% by weight of the amount of water-soluble polymer binder.

[0063] Experimental Examples

[0064] Experimental examples of the present description have found that basecoats and topcoats formed from water-soluble polymer binders and pigments surprisingly yield good smoothness and acceptable printing performance without necessitating any latex binder, enabling for the production of smooth coated paper or paperboard structures that would be compostable and bio-based.

[0065] Materials

[0066] Hydrocarb 60 - a coarse ground calcium carbonate pigment supplied by Omya

[0067] Hydrocarb 90 - a fine ground calcium carbonate pigment supplied by Omya

[0068] XP6170 - A hyperplaty clay pigment with a shape factor of about 70 provided by Imerys

[0069] Kaofine 90 - A fine kaolin clay pigment provided by Thiele [0070] Rhoplex P308 - A styrene-acrylic latex binder from Dow [0071] Ethylex 2015 - An ethylated starch binder provided by Tate & Lyle [0072] Sequarex 755 - a glyoxal -based crosslinker provided by Omnova [0073] Glycerin - a vegetable glycerin humectant from Amazon [0074] Sorbitol - a humectant from ADM [0075] Coating Compositions [0076] Basecoat compositions BC1 to BC11 were formulated with the weight ratios of respective components, i.e. Hydrocarb 60, XP6170, Rhoplex P308, Ethylex 2015, Glycerin, Sorbitol, and Sequarez 755, as shown in Table 1 below. The percent solids of the basecoat compositions were determined by measuring the weight difference in the basecoat compositions before and after drying. Basecoat composition BC1 represents a conventional basecoat composition. Basecoat compositions BC2 to BC11 are experimental basecoat compositions of the present description.

[0077] Topcoat compositions TCI to TC5 were formulated with the weight ratios of respective components, i.e. Hydrocarb 90, Kaofine 90, Rhoplex P308, Ethylex 2015, Glycerin, Sorbitol, and Sequarez 755, as shown in Table 2 below. The percent solids of the topcoat compositions were determined by measuring the weight difference in the topcoat compositions before and after drying. Topcoat composition TCI represents a conventional topcoat composition. Topcoat compositions TC2 to TC5 are experimental topcoat compositions of the present description.

[0078] As shown in Table 1, there were two different pigment systems used for the basecoat compositions. The first pigment system comprised a coarse ground calcium carbonate, which is a typical basecoat pigment. The second pigment system comprised blend of coarse ground calcium carbonate and hyperplaty clay. The reference basecoat composition BC1, considered to be conventional, had coarse ground calcium carbonate with a latex binder. All other basecoat compositions had water-soluble polymer binders.

[0079] The coating compositions included coating compositions with and without crosslinker, and with different levels of humectant. Crosslinker addition was limited by Food and Drug Administration (FDA) regulations, and the addition level was based on the amount of water- soluble polymer binder added, not the total coating. All coating compositions that contained a crosslinker had an addition level of 6% dry-on-dry based on the amount of water-soluble polymer binder. There were two types of FDA approved crosslinkers considered. In the experiments, a glyoxal-based crosslinker was used, and the maximum for this was 6% based on the amount of water-soluble polymer binder. There were many different humectants that could be chosen. In the experiments, it was decided to limit selection to bio-based materials, in particular, glycerin (also called glycerol) and sorbitol. The addition levels of humectants were based on the amount of water-soluble polymer binder, not on the total coating. Humectant levels of 0, 10, 20 and 30 %, based on weight, of the water-soluble polymer binder were tested.

TABLE 1

TABLE 2

[0080] Application of and Testing of Coating Compositions

[0081] Coating compositions BC1 to BC11 and TCI to TC5 were applied using pilot coating equipment. All coatings were applied to a 12”-wide at 400 fpm using a bent blade configuration. The substrate was a solid bleached sulfate (SBS) paperboard with a basis weight of about 1501b/3000 ft 2 and a caliper of about .013”. Each basecoat composition BC1 to BC11 was applied at three different coat weights, as shown in Table 3. Extended footage was run for each formula and coat weight combination. Samples were taken from each of these conditions for testing, and the remaining footage was used to produce topcoated prototypes. Basecoated samples were tested as-is without any additional processing. All testing was performed under TAPPI standard conditions. Print Surf roughness measurements were conducted using 10 psi pressure with a soft backing (PPS10S). The results are displayed in Table 3.

TABLE 3

[0082] Referring to Table 4, basecoats were covered one of the topcoat compositions TCI to TC5. For each basecoat/topcoat combination a range of topcoat weights were applied to create double coated prototypes having a range of basecoat/topcoat coat weights. The double coated samples were cut into sheets. These sheets were calendered using a single-nip soft roll calender. The soft roll had a Shore D hardness of 85. Sheets were calendered through one nip at 300 fpm, 225 °F and 150 pli pressure. Only calendered topcoated samples were tested. Print Surf roughness measurements were conducted using 10 psi pressure with a soft backing (PPS10S). The results are displayed in Table 4.

TABLE 4

[0083] Analysis of Roughness Results

[0084] The present description includes, but is not limited to, the following findings.

[0085] Fig. 4 plots roughness (PPS10S) of basecoated-only control sample BC1 vs. basecoated-only samples BC2 to BC5 over a range of basecoat weights. As demonstrated, if latex is simply replaced with water-soluble polymer binder, regardless of the presence or level of glycerin, the roughness increases.

[0086] Fig. 5 plots roughness (PPS10S) of basecoated-only control sample BC1 vs. basecoated-only samples BC6 to BC10 over a range of basecoat weights. As demonstrated, by using a pigmented system containing a hyperplaty clay, roughness of the water-soluble polymer binder samples is reduced relative to the latex control sample BC1. These examples represent two different humectants and a range of humectant levels. Thus, the blend of coarse ground calcium carbonate and hyperplaty clay was shown to have advantages over the all-carbonate pigment system.

[0087] Fig. 6 plots roughness (PPS10S) of basecoated-only control sample BC1 vs. basecoated-only samples BC8 to BC11 over a range of basecoat weights. As demonstrated, the improvement in roughness when using the blend of coarse ground calcium carbonate and hyperplaty clay occurs bot with and without crosslinker.

[0088] Fig. 7 plots roughness (PPS10S) after calendering of basecoated and topcoated control sample BC1/TC1 vs. basecoated and topcoated samples BC2/TC3 and BC4/TC3 over a range of basecoat weights. These are topcoated samples which all have all-carbonate basecoats.

BC1/TC1 is the combination of a typical latex basecoat with a typical latex topcoat which serves as a reference. BC2/TC3 and BC4/TC3 are combinations of basecoats of the present description with topcoats of the present description. Samples with a basecoat weight closest to 7.91b were selected for topcoating. The resulting coatings for BC2/TC3 and BC4/TC3 have acceptable surface roughness which is comparable the reference.

[0089] Fig. 8 plots roughness (PPS10S) after calendering of basecoated and topcoated control sample BC1/TC1 vs. basecoated and topcoated samples of the present description. These basecoated and topcoated samples of the present description coatings all use a 50/50 blend of coarse ground calcium carbonate and hyperplaty clay in the basecoat. The level of water-soluble polymer binder was held constant. Only the humectant levels were varied. Samples with a basecoat weight closest to 81b were used for topcoating. These samples demonstrate a wide range of combinations of the basecoats and topcoats of the present description that give equal or slightly better roughness than the reference basecoated and topcoated control sample BC1/TC1. Thus, by using hyperplaty clay in the basecoat, it was possible to make double coated samples without latex that have equal or better roughness values than the latex control sample.

[0090] Fig. 9 plots roughness (PPS10S) after calendering of basecoated and topcoated control sample BC1/TC1 vs. basecoated and topcoated samples of the present description. These basecoated and topcoated samples of the present description coatings all use a 50/50 blend of coarse ground calcium carbonate and hyperplaty clay in the basecoat. Samples with a basecoat weight closest to 9.71b were used for topcoating. Compared to the reference control sample BC1/TC1, the basecoated and topcoated samples of the present description have equal or better roughness values, regardless of the presence or absence of crosslinker.

[0091] Evaluation of Printing Performance

[0092] One method to evaluate the printing performance of coated paper is to measure the ink receptivity also known as ink holdout. In this test, a red high viscosity oil was applied in excess to the sample surface and allowed to sit for 2 minutes. After 2 minutes, the excess was thoroughly wiped away and the remaining stain was analyzed. The amount of ink remaining in the surface was measured as the decrease in brightness due to ink staining. This was reported as the percent decrease in brightness. The higher the number, the more ink was absorbed instead of being held out on the surface. The ink stain results are shown in Table 5. Tested samples included those that had both basecoat and topcoat weights of 8.51b. In some cases where a topcoat weight was not available, two samples with topcoat weights that bracket 8.5 were used. Table 5 shows that all of the samples with basecoat and topcoat of the present description, which include a water-soluble polymer binder and a pigment, have significantly improved ink holdout compared to the reference control sample BC1/TC1.

TABLE 5

[0093] Although various embodiments of the disclosed coated paper and coated paperboard structures have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the Claims.