JP2009102771A - Oil-repellent treatment agent, oil resistant paper, and method for producing the paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce oil resistant paper having a good oil resistance without employing a method having an increased amount of a cationic fluorine-containing copolymer used in imparting the oil resistance by using the cationic fluorine-containing copolymer having a carbon chain length of a perfluoroalkyl group less than 6. <P>SOLUTION: This method for producing the oil resistant paper includes adding an oil-repellent treatment agent consisting of (I) a composition containing (A) a cationic fluorine-containing copolymer having (a') a polymerization unit based on (a) a monomer having 1-6C perfluoroalkyl group, and (II) a composition containing (B) an amphoteric polyacrylamide-based resin, to the constitution materials of the paper. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an oil-resistant treatment agent, oil-resistant paper, and a method for producing the same.

  Oil-resistant paper treated with a compound having a perfluoroalkyl group (hereinafter referred to as “fluorinated oil-resistant paper”) is well known, and its barrier properties against liquids such as oil are used to make food wrapping paper, food wrapping containers, first It is used in a wide range of food packaging, freshness preservation agent packaging, oxygen scavenger packaging, and feed packaging.

In particular, fluorinated oil-resistant paper, unlike glassine paper, parchment paper, coated paper, laminated paper or plastic film, which is oil-resistant paper other than fluorine-based paper, has good water resistance and oil resistance while maintaining air permeability. Is preferably used in food packaging such as frying that does not like to be trapped inside, freshness preservation packaging or oxygen scavenger packaging that requires functional air permeability.
For example, Patent Document 1 below discloses a method for improving the barrier effect on fat by using a fluoroacrylic polymer in combination with starch or polyvinyl alcohol as a paper treating agent.

By the way, perfluoroalkyl groups used in conventional fluorine-based oilproofing agents mainly have 8 or more carbon atoms. In recent years, it has been recommended that the number of carbon atoms of a perfluoroalkyl group be less than 8 in a compound having a perfluoroalkyl group from the viewpoint of environmental impact.
On the other hand, in Patent Document 2 described below, a new alternative fluorine system using a short perfluoroalkyl group having 6 or less carbon atoms or a polyfluoropolyether instead of using a long perfluoroalkyl group in place of the conventional fluorine-based oilproofing agent. Oil resistance agents have been proposed.

It is known to use a cationic resin when producing an oil-resistant paper or oil-resistant paperboard using an anionic fluorine-containing oil-resistant agent (Non-patent Document 1 below).
In Patent Document 3 below, an anionic fluorine-containing oilproofing agent having a perfluoroalkyl group having a carbon chain length of 8 or more is internally or externally added, and a dry paper strength enhancer made of anionic or amphoteric polyacrylamide is added. A method for providing a paper having excellent oil resistance and strength by adding it internally is described.
Dyeing Industry Vol.43 No.6 P292-296 (1995) JP-A-9-209294 International Publication No. 2005/090423 Pamphlet JP 2005-213658 A

However, when an environment-friendly oil-proofing agent having a carbon chain length of a perfluoroalkyl group as described in Patent Document 2 of 6 or less is used for the oil-proofing treatment of paper, it is difficult to obtain sufficient oil resistance. In order to obtain the oil resistance, a large amount of an oil resistant agent may be required. For this reason, it is difficult to achieve sufficient oil resistance in, for example, a paperboard having a low basis weight thin paper or a low basis weight oil-resistant paper layer.
In addition, when a large amount of oil-proofing agent is used, there is a possibility that inconvenience may occur in the paper manufacturing process, such as peeling from the dryer surface in the drying process and poor drying due to poor adhesion depending on the paper making conditions.
Furthermore, when a cationic fluoropolymer is internally added as an oil-resistant agent, the amount of the oil-resistant agent is increased from the viewpoint of compatibility with the same cationic dry paper strength enhancer or wet paper strength enhancer. Since it is difficult to improve oil resistance, it is difficult to achieve both the tensile strength of paper and the oil resistance.

  The present invention has been made in view of the above circumstances, and when imparting oil resistance using a cationic fluorine-containing copolymer having a carbon chain length of a perfluoroalkyl group of 6 or less, the cationic fluorine-containing copolymer is provided. To provide an oil-resistant treatment agent capable of improving oil resistance without using a method of increasing the amount of coalescence, a method for producing oil-resistant paper using the oil-resistant treatment agent, and an oil-resistant paper obtained by the method. With the goal.

In order to solve the above-mentioned problems, the oil-resistant treatment agent of the present invention comprises a polymerized unit (a ′) based on the following monomer (a), a polymerized unit (b ′) based on the following monomer (b), and a single monomer Composition (I) containing cationic fluorine-containing copolymer (A) containing polymerized units (c ′) based on body (c), and composition (II) containing amphoteric polyacrylamide resin (B) It is characterized by consisting of.
Monomer (a): A compound represented by (ZY) _n X. However, wherein Z is or perfluoroalkyl group having 1 to 6 carbon atoms _{C m F 2m + 1 O (} CFWCF 2 O) d CFK- (m is an integer of 1 to 6, d is an integer from 1 to 4, W and K are Each independently represents a monovalent group represented by a fluorine atom or a trifluoromethyl group, Y represents a divalent organic group or a single bond not containing a fluorine atom, and n is 1 or 2. when n is _{1, X} represents _{-CR = CH 2, -COOCR = CH} 2, -OCOCR = CH 2, a -OCH ₂ -φ-CR = CH ₂ or -OCH = CH _2, and when n is 2 , X is _{-CH [- (CH 2) p} CR = CH 2] -, - CH [- (CH 2) p COOCR = CH 2] -, - CH [- (CH 2) p OCOCR = CH 2] - Or -OCOCH = CHCOO-, where R is Atom, a methyl group or a halogen atom, phi is a phenylene group, p is an integer of 0-4. When n is 2, two (ZY) present in one molecule may be the same as or different from each other.
Monomer ^{_{(b): CH 2 = CR}} 1 -G- (R 2 O) compound represented by q -R ^3. In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 2 to 4 carbon atoms, or an alkylene group having 2 to 3 carbon atoms in which part or all of the hydrogen atoms are substituted with a hydroxyl group. Q is an integer of 1 to 50, G is —COO (CH ₂ ) _r — or —COO (CH ₂ ) _t —NHCOO— (r is an integer of 0 to 4, t is an integer of 1 to 4) R ³ represents a hydrogen atom, a methyl group, an acryloyl group, a methacryloyl group or an allyl group.
Monomer ^{_{(c): CH 2 = CR}} 4 -M-Q-NR 5 R 6 or ^{_{CH 2 = CR 4 -M-Q}} -N (O) a compound represented by R 5 ^{R 6.} In the formula, R ⁴ represents a hydrogen atom or a methyl group, M represents —COO— or —CONH—, and Q represents an alkylene group having 2 to 4 carbon atoms or a part or all of the hydrogen atoms substituted with a hydroxyl group. Represents an alkylene group having 2 to 3 carbon atoms, and R ⁵ and R ⁶ each independently represents a benzyl group, an alkyl group having 1 to 8 carbon atoms, or a carbon atom having 2 to 3 carbon atoms in which a part of hydrogen atoms is substituted with a hydroxyl group. 3, R ⁵ , R ⁶ and a nitrogen atom may form a piperidino group or a pyrrolidinyl group, and R ⁵ , R ⁶ , an oxygen atom and a nitrogen atom may form a morpholino group.

In (Z—Y) _n X of the monomer (a), Z is a C 1-6 perfluoroalkyl group, Y is a divalent organic group containing no fluorine atom, and X is —OCOCR. ═CH ₂ or —OCOCH═CHCOO— (R represents a hydrogen atom, a methyl group or a halogen atom) is preferred.
The cationic fluorine-containing copolymer (A) is 70 to 90% by mass of the polymerized unit (a ′), 3 to 20% by mass of the polymerized unit (b ′), and of the polymerized unit (c ′). It is preferable to contain 7-25 mass%.

The present invention provides an oil-resistant paper manufacturing method comprising an oil-resistant treatment step of adding the oil-resistant treatment agent of the present invention to a constituent material of paper.
In the oil-resistant treatment step, the composition (II) containing the amphoteric polyacrylamide resin (B) and the composition (I) containing the cationic fluorine-containing copolymer (A) are added to the pulp slurry. The method of adding in order is preferable.
Moreover, this invention provides the oil-resistant paper manufactured using the manufacturing method of the oil-resistant paper of this invention.

According to the oil-resistant treatment agent of the present invention, a method for increasing the amount of the cationic fluorine-containing copolymer used even though the carbon chain length of the perfluoroalkyl group in the cationic fluorine-containing copolymer is 6 or less. Regardless of this, good oil resistance can be imparted.
According to the method for producing oil-resistant paper of the present invention, the amount of the cationic fluorine-containing copolymer used is increased even though the carbon chain length of the perfluoroalkyl group in the cationic fluorine-containing copolymer is 6 or less. Regardless of the method used, oil-resistant paper having good oil resistance can be produced.
The oil resistant paper of the present invention has good oil resistance.

<Amotropic polyacrylamide resin (B)>
The amphoteric polyacrylamide resin (B) used in the present invention is not particularly limited as long as it is an amphoteric polyacrylamide resin. The polyacrylamide resin is a polymer containing polymerized units based on acrylamide or a derivative thereof, an acrylamide copolymer obtained by copolymerizing acrylamide and a monomer copolymerizable therewith, and a modified product of the acrylamide copolymer. And modified products of homopolymers of acrylamide.
In the present invention, “amphoteric” means that the cation value of the polyacrylamide resin represented by the following formula (A) is 0.5 to 1.5 (meq / g).
The cation value is calculated by the following method. First, 0.05 g of a polyacrylamide resin sample (usually an aqueous solution) to be measured is precisely weighed and made up to 100 ml with distilled water. Remove 20 ml of this and add 0.5 ml of 0.1N hydrochloric acid and 2-3 drops of toluidine blue indicator. This liquid is titrated with a 1/400 (= 0.0025) N polyvinyl potassium sulfate solution (hereinafter referred to as PVSK), and the end point is the point at which the liquid has changed color from blue to reddish purple.
In the following formula (A), x is a PSVK titration (ml), F is a factor of PSVK, y is a mass (g) of a polyacrylamide resin sample, z is a solid content concentration (mass of the polyacrylamide resin in the sample) %).

As the amphoteric polyacrylamide resin (B), those that are amphoteric can be appropriately selected from known acrylamide copolymers, Mannich-modified polyacrylamide resins, and Hoffman-decomposed polyacrylamide resins. . Of these, amphoteric acrylamide copolymers are preferred.
The amphoteric polyacrylamide resin (B) may be used alone or in combination of two or more.

Examples of the amphoteric polyacrylamide resin (B) include a copolymer of acrylamide, at least one cationic monomer selected from the following, and at least one anionic monomer selected from the following.
Examples of the cationic monomer include the following compounds.
Dialkylaminoalkyl (meth) acrylamides such as dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, and diethylaminopropyl (meth) acrylamide.
Dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and diethylaminopropyl (meth) acrylate.
A quaternary obtained by reacting the above dialkylaminoalkyl (meth) acrylamide or the above dialkylaminoalkyl (meth) acrylate with a quaternizing agent such as dimethyl sulfate, diethyl sulfate, methyl chloride, benzyl chloride, methyl sulfate, epichlorohydrin and the like. Amino group-containing monomers, such as acrylamidopropylbenzyldimethylammonium chloride, methacryloyloxyethyldimethylbenzylammonium chloride, acryloyloxyethyldimethylbenzylammonium chloride, (meth) acryloylaminoethyltrimethylammonium chloride, (meth) acryloylaminoethyl Triethylammonium chloride, (meth) acryloyloxyethyl trimethylammonium chloride, (meth) acryloyloxyethyl Li ethyl ammonium chloride.
In addition, vinylamine and vinylamidines derived from diallyldimethylammonium chloride, allylamine, and vinylformamide can also be used.

  Anionic monomers include (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid, (anhydrous) citraconic acid, vinyl sulfonic acid, (meth) allyl sulfonic acid, styrene sulfonic acid, sulfopropyl (meth) Α, β-unsaturated carboxylic acids or α, β-unsaturated sulfones such as acrylate, 4-sulfobutyl (meth) acrylate, 2-sulfoethyl (meth) acrylate, 2- (meth) acrylamide-2-methylpropanesulfonic acid, etc. Examples thereof include acids, and alkali metal salts, ammonium salts, and amine salts thereof.

<Composition (II)>
The composition (II) in the present invention contains an amphoteric polyacrylamide resin (B). The composition (II) may contain a solvent and various additives in addition to the amphoteric polyacrylamide resin (B).
The composition (II) containing the amphoteric polyacrylamide resin (B) is available from a commercial product. For example, FD-7290 (product name, copolymerized polyacrylamide resin) manufactured by Seiko PMC may be used.

<Cationic fluorine-containing copolymer (A)>
The cationic fluorine-containing copolymer (A) used in the present invention (hereinafter sometimes simply referred to as a fluorine-containing copolymer (A)) is a polymerized unit (a ′) based on the monomer (a), It contains a polymerized unit (b ′) based on the monomer (b) and a polymerized unit (c ′) based on the monomer (c).
The fluorine-containing copolymer (A) has an amino group (which may be substituted) derived from the monomer (c) and exhibits a cationic property. The fluorine-containing copolymer (A) is water dispersible.

<Monomer (a) / Polymerized unit (a ′)>
The monomer (a) is a compound represented by (ZY) _n X. The polymerized unit (a ′) is a polymerized unit formed by cleavage of the double bond of the polymerizable unsaturated group of the monomer (a).

Z in (ZY) _n X is a C 1-6 perfluoroalkyl group (hereinafter sometimes referred to as R ^F group) or C _m F _{2m + 1} O (CFWCF ₂ O) _d CFK- (m is 1 D is an integer of 1 to 4. d is an integer of 1 to 4. W and K are each independently a group represented by a fluorine atom or a trifluoromethyl group (—CF ₃ ).
Z is preferably a C 1-6 R ^F group, and F (CF ₂ ) ₂ —, F (CF ₂ ) ₃ —, F (CF ₂ ) ₄ —, F (CF ₂ ) ₅ —, F ( _{CF 2) 6 -, (CF} 3) 2 CF (CF 2) 2 - it is more _{preferable, F (CF 2) 4 -} , F (CF 2) 5 -, F (CF 2) 6 - is most preferred.

Y is a divalent organic group containing no fluorine atom or a single bond. Y is preferably a divalent organic group. Y ^{is, -R M -T-R N -} 2 divalent group represented by is more preferable. In the formula, R ^M and R ^N each independently represent a single bond or a saturated or unsaturated hydrocarbon group having 1 to 22 carbon atoms which may contain one or more etheric oxygen atoms. T is a single _{bond, -OCONH -, - CONH -,} - SO 2 NH -, - SO 2 NR '- (R' is an alkyl group having 1 to 6 carbon atoms) or -NHCONH-.
The above as Y ^-R M ^{-T-R N} - is an alkylene group having 1 to 10 carbon _{atoms, -CH = CHCH 2 -, -} (CH 2 CHR''O) j CH 2 CH 2 - (j is 1 -C ₂ H ₄ OCONHC ₂ H ₄ —, —C ₂ H ₄ OCOOC ₂ H ₄ —, or —COOC ₂ H ₄ — is preferred. , more preferably an alkylene group having 1 to 10 carbon _{atoms, -CH 2 -, - CH 2} CH 2 -, - (CH 2) 11 - or _{-CH 2 CH 2 CH (CH 3} ) - more preferred.

n is 1 or 2.
X is a polymerizable unsaturated group, and when n is 1, -CR = CH ₂ , -COOCR = CH ₂ , -OCOCR = CH ₂ , -OCH ₂ -φ-CR = CH ₂ or -OCH = is CH _2, and when n is _{2 -CH [- (CH 2)} p CR = CH 2] -, - CH [- (CH 2) p COOCR = CH 2] -, - CH [- (CH 2 _{) p OCOCR = CH 2] -} , or -OCOCH = CHCOO- (R is a hydrogen atom, a methyl group or a halogen atom .φ is a phenylene group .p is an integer from 0 to 4).. When n is 2, two (ZY) present in one molecule may be the same as or different from each other.
X is preferably —OCOCR═CH ₂ or —OCOCH═CHCOO—, more preferably —OCOCR═CH ₂ , since it is excellent in solubility in a solvent and can be easily subjected to emulsion polymerization. As R, since it is excellent in polymerizability, a hydrogen atom, a halogen atom (a fluorine atom, a chlorine atom, etc.) or an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable.

As the monomer (a), Z is a C 1-6 perfluoroalkyl group, Y is a divalent organic group containing no fluorine atom, and X is —OCOCR═CH ₂ or — What is OCOCH = CHCOO- is preferable.
As particularly preferred specific examples, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate, 3,3,4,4,5,5 , 6,6,6-nonafluorohexyl methacrylate is preferred.
Monomer (a) may use 1 type and may use 2 or more types.

<Monomer (b) / Polymerized unit (b ′)>
Monomer (b) is a compound represented by _{^{CH 2 = CR 1 -G- (R}} 2 O) q -R 3. The polymerized unit (b ′) is a polymerized unit formed by cleavage of the ethylenic double bond of the monomer (b).
R ¹ is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, a methyl group, a (meth) acryloyl group or an allyl group, and R ² is an alkylene group having 2 to 4 carbon atoms or a part of a hydrogen atom or All are C2-C3 alkylene groups substituted with hydroxyl groups. Two or more types of alkylene groups having different carbon numbers may be contained in one molecule.
In the monomer (b), when two or more kinds of alkylene groups having different carbon numbers are included as — (R ² O) _q —, the arrangement of these repeating units may be a block shape or a random shape. Good. q is an integer of 1 to 50, preferably 1 to 30, and more preferably 1 to 15.
G is -COO _{(CH 2) r} - is or _{-COO (CH 2) t -NHCOO- (} r is an integer of 0 to 4, t is an integer from 1 to 4.).
Monomer (b) may use 1 type and may use 2 or more types.

R ³ is preferably a hydrogen atom or a (meth) acryloyl group. R ² is preferably an alkylene group having 2 to 4 carbon atoms. G is preferably —COO (CH ₂ ) _r — (r is an integer of 0 to 4). When R ³ is a (meth) acryloyl group, the fluorinated copolymer tends to have a three-dimensional network structure, and the fluorinated copolymer adheres firmly to the substrate and is excellent in durability. As the monomer (b), a compound in which R ³ is a (meth) acryloyl group and a compound in which R ³ is a hydrogen atom may be used in combination.

As a specific example of the monomer (b),
2-hydroxyethyl (meth) acrylate,
2-hydroxypropyl (meth) acrylate,
2-hydroxybutyl (meth) acrylate,
4-hydroxybutyl (meth) acrylate,
Polyoxyethylene glycol mono (meth) acrylate,
Polyoxypropylene glycol mono (meth) acrylate,
Methoxy polyoxyethylene glycol (meth) acrylate,
Trioxyethylene glycol di (meth) acrylate,
Tetraoxyethylene glycol di (meth) acrylate,
Polyoxyethylene glycol di (meth) acrylate,
Acryloyloxypolyoxyethylene glycol methacrylate,
2-hydroxy-3-acryloyloxypropyl (meth) acrylate,
Poly (oxypropylene-oxybutylene) glycol di (meth) acrylate,
Poly (oxyethylene-oxypropylene) glycol di (meth) acrylate,
Examples include poly (oxyethylene-oxybutylene) glycol di (meth) acrylate.

Among these, as the monomer (b), polyoxyethylene glycol mono (meth) acrylate,
2-hydroxyethyl (meth) acrylate,
2-hydroxypropyl (meth) acrylate,
2-hydroxybutyl (meth) acrylate,
4-hydroxybutyl (meth) acrylate,
Trioxyethylene glycol di (meth) acrylate,
Tetraoxyethylene glycol di (meth) acrylate,
Polyoxyethylene glycol di (meth) acrylate,
Poly (oxyethylene-oxypropylene) glycol di (meth) acrylate is more preferred.
More preferably, polyoxyethylene glycol mono (meth) acrylate,
2-hydroxyethyl (meth) acrylate,
4-hydroxybutyl (meth) acrylate,
Trioxyethylene glycol di (meth) acrylate (hereinafter sometimes referred to as 2,2′ethylenedioxydiethyldimethacrylate),
Tetraoxyethylene glycol di (meth) acrylate,
Poly (oxyethylene-oxypropylene) glycol di (meth) acrylate,
Polyoxyethylene glycol di (meth) acrylate.

<Monomer (c) / Polymerized unit (c ′)>
Monomer (c) _is a ^{CH 2 = CR 4 -M-Q} -NR 5 R 6 or ^{_{CH 2 = CR 4 -M-Q}} -N (O) a compound represented by R 5 ^{R 6.} The polymerized unit (c ′) is a polymerized unit formed by cleavage of the ethylenic double bond of the monomer (c).
In the formula, R ⁴ is a hydrogen atom or a methyl group, M is —COO— (ester bond) or —CONH— (amide bond), and Q is a C 2-4 alkylene group or a part of a hydrogen atom. Or an alkylene group having 2 to 3 carbon atoms, all of which are substituted with hydroxyl groups, and R ⁵ and R ⁶ are each independently a benzyl group, an alkyl group having 1 to 8 carbon atoms, or a part of hydrogen atoms substituted with hydroxyl groups. And an alkyl group having 2 to 3 carbon atoms. R ⁵ , R ⁶ and the nitrogen atom may form a piperidino group or a pyrrolidinyl group, and R ⁵ , R ⁶ , an oxygen atom and a nitrogen atom may form a morpholino group.

M is preferably —COO—. Q is preferably an alkylene group having 2 to 4 carbon atoms. R ⁵ and R ⁶ are preferably an alkyl group having 1 to 8 carbon atoms.
Monomer (c) may use 1 type and may use 2 or more types.

As the monomer (c),
N, N-dimethylaminoethyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
N, N-dimethylaminopropyl (meth) acrylate,
N, N-diethylaminopropyl (meth) acrylate,
N, N-diisopropylaminoethyl (meth) acrylate,
N, N-diethylaminopropyl (meth) acrylamide,
N- (meth) acryloylmorpholine,
N- (meth) acryloylpiperidine,
N, N-dimethylaminooxide ethyl (meth) acrylate is preferred.
Among these, N, N-dimethylaminoethyl methacrylate or N, N-diethylaminoethyl methacrylate is more preferable.

<Other monomer (d)>
The fluorine-containing copolymer (A) is a monomer other than the above-mentioned monomers (a) to (c) as long as the effects of the present invention are not impaired, and the monomers (a) to (c) You may have the polymerization unit (d ') based on the other monomer (d) which can be copolymerized.
Although monomer (d) is not specifically limited, For example, 3,5-dimethylpyrazole adduct of 2-isocyanatoethyl (meth) acrylate, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane When one or more selected from 3-methacryloyloxypropyltriethoxysilane and 3-methacryloyloxypropyldiethoxyethylsilane are used, the water repellency, oil resistance and water resistance are further improved.

The fluorine-containing copolymer (A) is
3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate as monomer (a), and 3,3,4,4,5 One or more selected from 5,6,6,6-nonafluorohexyl methacrylate,
As monomer (b), polyoxyethylene glycol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, triethylene glycol di (meth) ) One or more selected from acrylate, tetraethylene glycol di (meth) acrylate, and polyoxyethylene glycol di (meth) acrylate,
Fluorine-containing copolymer polymerized using at least one selected from N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, and N, N-diethylaminooxide ethyl methacrylate as monomer (c) Is preferred.

The fluorine-containing copolymer (A) is 70 to 90% by mass of the polymerized unit (a ′) based on the monomer (a), and 3 to 20% by mass of the polymerized unit (b ′) based on the monomer (b). % And 7 to 25% by mass of the polymerized unit (c ′) based on the monomer (c).
The more preferable range of the content of each polymerized unit is that the polymerized unit (a ′) is 72 to 80% by mass, the polymerized unit (b ′) is 8 to 16% by mass, and the polymerized unit (c ′) is 9 to 18% by mass. %.
When the fluorine-containing copolymer (A) contains a polymer unit (d ′) based on the other monomer (d), the content ratio of the polymer unit (d ′) based on the other monomer (d) Is preferably 5% by mass or less, and more preferably 2% by mass or less.
Within the above range, good oil resistance can be obtained in the oil resistant paper treated with the fluorine-containing copolymer of the present invention. Further, the fluorine-containing copolymer (A) having a polymerization unit composition within the above range is excellent in adhesiveness to paper.
The content ratio of each polymerization unit in the present invention is a value obtained from the charged amount of each monomer, assuming that the mass of the polymerization unit derived from the polymerization initiator and the chain transfer agent in the fluorine-containing copolymer is 0 (zero). It is.

The mass average molecular weight (Mw) of the fluorinated copolymer (A) is preferably from 5,000 to 100,000, more preferably from 20,000 to 90,000. When the mass average molecular weight is not less than the lower limit of the above range, the oil resistance is excellent, and when it is not more than the upper limit, the film forming property and the liquid stability are excellent.
The mass average molecular weight of the fluorine-containing copolymer (A) in the present specification is obtained by measuring by gel permeation chromatography using a calibration curve prepared using a standard polymethyl methacrylate sample. It is a converted molecular weight.

<Method for producing cationic fluorine-containing copolymer (A)>
The fluorine-containing copolymer (A) in the present invention can be obtained by performing a monomer polymerization reaction in a polymerization solvent using a known method.
Moreover, after obtaining a fluorine-containing copolymer (A) by the polymerization reaction of a monomer, it is preferable to amine-treat the amino group in this copolymer (A). This improves the dispersibility of the copolymer (A) in an aqueous medium.
An acid or the like is preferably used for amine chloride, and an acid having a dissociation constant or primary dissociation constant of 10 ⁻⁵ or more is more preferable. As the acid, hydrochloric acid, hydrobromic acid, sulfonic acid, nitric acid, phosphoric acid, acetic acid, formic acid, propionic acid, lactic acid and the like are preferable, and acetic acid is more preferable.
Further, instead of amine-treating the amino group of the fluorinated copolymer (A) with an acid, methyl iodide, ethyl iodide, dimethyl sulfate, diethyl sulfate, benzyl chloride, trityl phosphate, methyl p-toluene sulfonate Etc. may be used to convert to a quaternary ammonium salt (also referred to as quaternary chloride).

<Composition (I)>
The composition (I) in the present invention contains a cationic fluorine-containing copolymer (A). The composition (I) is preferably a composition obtained by dispersing or dissolving the fluorine-containing copolymer (A) in an aqueous medium. The aqueous medium only needs to be a liquid containing water and a volatile organic solvent content of 1% by mass or less. Specifically, water or an azeotrope containing water is preferable.
In the present specification, the volatile organic solvent in the composition (I) means an organic solvent that volatilizes when the composition (I) is stored at room temperature, and specifically 1 × 10 ^5. An organic solvent having a boiling point at Pa (hereinafter, simply referred to as “boiling point”) of 100 ° C. or less. Note that the solvent that forms an azeotrope with water is not included in the volatile organic solvent.

The composition (I) may contain various additives. Further, known additives (not including the amphoteric polyacrylamide resin (B) in the present invention) used in the paper manufacturing process, such as paper strength agents, sizing agents, antifoaming agents, penetrants, and the like are included as necessary. You may let them.
For example, starch, cationic modified starch, hydroxyethylated starch, oxidized starch, enzyme modified starch, polyvinyl alcohol, polyamidoamine, polyamidoamine epichlorohydrin modified, urea or melamine formaldehyde condensate or precondensate, methylol-dihydroxy Resins such as ethylene-urea and derivatives thereof, uron, methylol-ethylene-urea, methylol-propylene-urea, methylol-triazone, dicyandiamide-formaldehyde condensate, AKD, cationic acrylic resin, dendrimer type alcohol penetrant, acetylene Examples include penetrants such as glycol penetrants; antifoaming agents such as silicone-based antifoaming agents, dendrimer-type alcohol-based antifoaming agents, and acetylene glycol-based antifoaming agents.

<Oil-resistant treatment agent>
The oil-resistant treatment agent of the present invention comprises the composition (I) and the composition (II). The composition (I) and the composition (II) may be separate or mixed. Preferably it is used as a separate body.

<Oil-resistant paper manufacturing method>
The method for producing oil-resistant paper of the present invention includes an oil-resistant treatment step of adding an oil-resistant treatment agent to the paper constituent material. The oil-resistant paper in the present invention is a concept including oil-resistant paper and paperboard.
In the present invention, the constituent material of the paper to which the oil-proofing agent is added is mainly composed of cellulose fibers such as pulp and rayon, and other fillers; dispersion media; paper strength agents, sizing agents, antifoaming agents. , A known additive (not including the amphoteric polyacrylamide resin (B) in the present invention) used in the paper manufacturing process, such as a penetrating agent, a coagulant, and a yield improver. Good.
Examples of the pulp include bleached sulfite pulp and kraft pulp, unbleached chemical pulp, groundwood pulp, thermomechanical pulp, mechanical pulp, recycled pulp, and the like. Chemical pulp is preferable from the viewpoint of expression of oil resistance.

  In the present invention, the oil-resistant treatment step is preferably performed by a method (internal addition) in which an oil-resistant treatment agent is added before the dry part of the papermaking step in order to achieve better oil resistance and air permeability.

In the case of internal addition, a method of adding the composition (I) and the composition (II) to the pulp slurry before forming the paper layer in the paper making process is preferable. Internal addition with a pulp mold for directly molding a paper container is also possible.
At this time, a mixture in which the composition (I) and the composition (II) are mixed in advance may be added, and the composition (I) and the composition (II) are prepared separately, and these are added simultaneously. One of them may be added first, and then the other may be added.
Preferably, the composition (II) containing the amphoteric polyacrylamide resin (B) is added first, and then the composition (I) containing the cationic fluorine-containing copolymer (A) is added. It is preferable to add the amphoteric polyacrylamide resin (B) first in that the composition (I) containing the cationic fluorine-containing copolymer (A) can be efficiently fixed to the pulp.
In the case of internal addition, the addition amount of the amphoteric polyacrylamide-based resin (B) is preferably 0.05 to 1.0% by mass, and 0.1 to 0.5% by mass with respect to the dry pulp mass in the pulp slurry. More preferred. If it is less than 0.05% by mass, it is difficult to obtain a sufficient oil resistance effect, and if it exceeds 1.0% by mass, it is not preferable in terms of chemical cost and easy sticking to a dry dryer.
0.3-1.2 mass% is preferable with respect to the dry pulp mass in a pulp slurry, and, as for the addition amount of a cationic fluorine-containing copolymer (A), 0.4-0.7 mass% is more preferable. If it is less than 0.3% by mass, it is difficult to obtain a sufficient oil resistance effect, and if it exceeds 1.2% by mass, it is not preferable in terms of chemical cost and easy peeling from a dry dryer.

The oil-resistant paper of the present invention thus obtained contains the fluorine-containing copolymer (A) and the amphoteric polyacrylamide resin (B). As shown in the examples described later, the amount of the fluorine-containing copolymer (A) used is increased by subjecting the fluorine-containing copolymer (A) and the amphoteric polyacrylamide resin (B) to oil resistance treatment. Even if not, good oil resistance can be obtained.
That is, according to the present invention, although the perfluoroalkyl group contained in the fluorinated copolymer (A) is a shorter-chain perfluoroalkyl group than in the past, an oil-resistant paper exhibiting good oil resistance, It can be manufactured without causing inconveniences in the manufacturing process.
Therefore, sufficient oil resistance can be imparted to, for example, a paperboard having a low basis weight thin paper or a low basis weight oil-resistant paper layer.
Further, as shown in the examples described later, the tensile strength of the paper can be improved simultaneously with the improvement of oil resistance.

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples. In the following, “%” is “% by mass” unless otherwise specified.
The performance evaluation was performed by the following method.
[Oil resistance: kit test]
The kit test was conducted by the following method according to the TAPPI T559cm-02 method. In the test, a kit solution in which castor oil, toluene and normal heptane were mixed at a volume ratio shown in Table 1 was used. The result of the test is represented by a kit number, and the higher the number, the better the oil resistance. In the kit test, the tendency of the oil resistance of the test paper can be known in a very short time (15 seconds), and it is widely used for evaluating the oil resistance of the paper. This evaluation result has a meaning as an index for the surface tension of the paper surface.

  First, the test paper was placed on a clean, flat black surface, and one drop of the mixed solution of kit number 12 (kit solution) was dropped onto the test paper from a height of 13 mm. 15 seconds after the dropping (contact time: 15 seconds), the mixed solution dropped with a clean blotting paper was removed, and the surface of the paper contacted with the mixed solution was visually observed. When the surface color was dark, the same operation was performed with the mixed solution of kit number 11, and the same operation was repeated while gradually decreasing the kit number until the kit number where the surface color did not darken. Evaluate by the first (highest) kit number that does not darken the surface color.

[Oil resistance: soybean oil test]
In order to sufficiently evaluate in more realistic use conditions, the resistance to “soybean oil”, which is a general vegetable edible fat, was evaluated by the following method.
First, about 0.5 mL of soybean oil was dropped on a 5 cm × 5 cm test paper and held at 60 ° C. and 65% RH for 2 hours using an environmental tester. After taking out from the environmental testing machine, the soybean oil on the test paper was removed, and the stain of the soybean oil on the test paper was visually observed.
“○” indicates that there are no traces of stain, “△” indicates that traces of stain remain, and “×” indicates that stains remain in contact with soybean oil, spreading over half of the test paper area. The test piece was evaluated in five grades, “XXX”, and the test sample spreading through the entire test paper.

[Dry tensile strength]
It was measured according to the standard of JIS P 8113-98.

<Preparation Example 1: Preparation of cationic fluorine-containing copolymer (A)>
In a 1 L stainless steel reaction vessel, 11,4.0 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl methacrylate (purity 99.6%), 16.5 g of 2-hydroxyethyl methacrylate, 18.0 g of N, N-diethylaminoethyl methacrylate, 1.5 g of 2,2 ′ ethylenedioxydiethyl dimethacrylate, 350 g of acetone and dimethyl 2,2′-azobis (2-methyl 1.2 g of propionate) was charged, and nitrogen substitution was repeated three times. Polymerization was carried out by carrying out a polymerization reaction at 65 ° C. for 16 hours at a stirring speed of 350 rpm. A pale yellow solution with a solids concentration of 30% was obtained. When the molecular weight of the obtained copolymer was examined by gel permeation chromatography, the mass average molecular weight was 80,000.

  To 100 g of the obtained pale yellow solution, 2 g of acetic acid and 120 g of ion-exchanged water were added, and the mixture was stirred and dispersed with an agitator. Subsequently, the mixture was heated to a temperature in the range of 65 ° C. to 95 ° C. under reduced pressure to distill away acetone, thereby obtaining a pale orange transparent copolymer aqueous dispersion. An aqueous dispersion having a solid content concentration of 20% by mass was prepared from this aqueous dispersion using ion-exchanged water. . Thus, an aqueous dispersion (composition (I)) containing the cationic fluorine-containing copolymer (A) was obtained.

<Example 1: Production of internally added industrial paper>
NBKP (softwood bleached kraft pulp) and LBKP (hardwood bleached kraft pulp) were used as raw material pulp.
The mixture was mixed so that the mass ratio of LBKP / NBKP was 7/3, and beaten by a PFI mill (JIS P8221-2). s. A pulp slurry, f, was prepared.
Next, as a composition (II) containing an amphoteric polyacrylamide resin (B) in a pulp slurry whose pulp concentration is adjusted to 3%, FD-7290 (product name, manufactured by Seiko PMC, copolymer polyacrylamide type) Resin, cation number 0.85) was added and stirred. Thereafter, the aqueous dispersion (composition (I)) containing the cationic fluorine-containing copolymer (A) obtained in Preparation Example 1 was added and stirred.
Addition amount (solid content) and cationic fluorine-containing amphoteric polyacrylamide resin (indicated in the table as amphoteric PAM) when the dry pulp mass of the whole pulp in the pulp slurry is 100% by mass The ratio (unit: mass%) of the addition amount (solid content) of the copolymer (A) is shown in Table 2 (the same applies to Table 3).
Using the pulp slurry to which the amphoteric polyacrylamide resin (B) and the cationic fluorine-containing copolymer (A) were added in this way, the basis weight was about 50 g / m according to the method for preparing the handsheet for test of JIS P 8222. Paper No. ² was made and dried at 105 ° C. for 60 seconds using a drum dryer to obtain paper (internally added paper).
Using the obtained paper as a test paper, the above-described kit test and soybean oil test were conducted to evaluate the oil resistance, and the dry tensile strength (unit: N) was measured. The results are shown in Table 2.

(Examples 2 to 4)
Paper (internally added paper) in the same manner as in Example 1 except that the addition amount of the amphoteric polyacrylamide resin (B) and the addition amount of the cationic fluorine-containing copolymer (A) were changed as shown in Table 2. ) Was manufactured and tested. The results are shown in Table 2.

(Comparative Example 1)
In Example 3, paper (internally added paper) was produced and tested in the same manner except that the composition (II) was not added. The results are shown in Table 3.

(Comparative Examples 2 and 4)
Instead of the composition (II) containing the amphoteric polyacrylamide resin (B), a composition containing a commercially available cationic polyacrylamide resin (referred to as cationic PAM in the table) (cation number 1.76) Alternatively, a paper (internally added paper) is produced in the same manner as in Example 3 except that a composition containing a commercially available anionic polyacrylamide resin (in the table, described as anionic PAM) is used. A test was conducted. The results are shown in Table 3.

(Comparative Examples 3 and 5)
Instead of the composition (II) containing the amphoteric polyacrylamide resin (B), a composition containing a commercially available cationic polyacrylamide resin (cationic value 1.76) or a composition containing a commercially available anionic polyacrylamide resin A paper (internally added paper) was produced and tested in the same manner as in Example 4 except that the product was used. The results are shown in Table 3.

From the results of Tables 2 and 3, when Examples 1 to 4 and Comparative Example 1 are compared, it can be seen that the addition of the amphoteric polyacrylamide resin (B) improves the oil resistance and also improves the tensile strength.
A comparison between Example 3 and Comparative Example 2 and Example 4 and Comparative Example 3 in which the addition amounts of the cationic fluorine-containing copolymer (A) and the polyacrylamide resin are equivalent to each other. In Examples 3 and 4 to which (B) was added, the evaluation of the kit test was improved and the results of the soybean oil test were equivalent or improved compared to Comparative Examples 2 and 3 to which the cationic polyacrylamide resin was added. Also, the tensile strength was excellent.
In Examples 1 and 2, the amount of the cationic fluorine-containing copolymer (A) added is smaller than in Comparative Examples 2 and 3, but the kit test and soybean oil test are equivalent or better in Examples 1 and 2. The tensile strengths of Examples 1 and 2 were superior.
Comparative Examples 4 and 5 to which the anionic polyacrylamide resin was added had poor oil resistance despite using the cationic fluorine-containing copolymer (A).

Claims (6)

A cation comprising a polymerized unit (a ′) based on the following monomer (a), a polymerized unit (b ′) based on the following monomer (b), and a polymerized unit (c ′) based on the following monomer (c) An oil-resistant treatment agent comprising: a composition (I) containing an ionic fluorine-containing copolymer (A); and a composition (II) containing an amphoteric polyacrylamide resin (B).
Monomer (a): A compound represented by (ZY) _n X. However, wherein Z is or perfluoroalkyl group having 1 to 6 carbon atoms _{C m F 2m + 1 O (} CFWCF 2 O) d CFK- (m is an integer of 1 to 6, d is an integer from 1 to 4, W and K are Each independently represents a monovalent group represented by a fluorine atom or a trifluoromethyl group, Y represents a divalent organic group or a single bond not containing a fluorine atom, and n is 1 or 2. when n is _{1, X} represents _{-CR = CH 2, -COOCR = CH} 2, -OCOCR = CH 2, a -OCH ₂ -φ-CR = CH ₂ or -OCH = CH _2, and when n is 2 , X is _{-CH [- (CH 2) p} CR = CH 2] -, - CH [- (CH 2) p COOCR = CH 2] -, - CH [- (CH 2) p OCOCR = CH 2] - Or -OCOCH = CHCOO-, where R is Atom, a methyl group or a halogen atom, phi is a phenylene group, p is an integer of 0-4. When n is 2, two (ZY) present in one molecule may be the same as or different from each other.
Monomer ^{_{(b): CH 2 = CR}} 1 -G- (R 2 O) compound represented by q -R ^3. In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 2 to 4 carbon atoms, or an alkylene group having 2 to 3 carbon atoms in which part or all of the hydrogen atoms are substituted with a hydroxyl group. Q is an integer of 1 to 50, G is —COO (CH ₂ ) _r — or —COO (CH ₂ ) _t —NHCOO— (r is an integer of 0 to 4, t is an integer of 1 to 4) R ³ represents a hydrogen atom, a methyl group, an acryloyl group, a methacryloyl group or an allyl group.
Monomer ^{_{(c): CH 2 = CR}} 4 -M-Q-NR 5 R 6 or ^{_{CH 2 = CR 4 -M-Q}} -N (O) a compound represented by R 5 ^{R 6.} In the formula, R ⁴ represents a hydrogen atom or a methyl group, M represents —COO— or —CONH—, and Q represents an alkylene group having 2 to 4 carbon atoms or a part or all of the hydrogen atoms substituted with a hydroxyl group. Represents an alkylene group having 2 to 3 carbon atoms, and R ⁵ and R ⁶ each independently represents a benzyl group, an alkyl group having 1 to 8 carbon atoms, or a carbon atom having 2 to 3 carbon atoms in which a part of hydrogen atoms is substituted with a hydroxyl group. 3, R ⁵ , R ⁶ and a nitrogen atom may form a piperidino group or a pyrrolidinyl group, and R ⁵ , R ⁶ , an oxygen atom and a nitrogen atom may form a morpholino group. In (Z—Y) _n X of the monomer (a), Z is a C 1-6 perfluoroalkyl group, Y is a divalent organic group containing no fluorine atom, and X is —OCOCR. The oil-resistant treatment agent according to claim 1, which is ═CH ₂ or —OCOCH═CHCOO— (R represents a hydrogen atom, a methyl group or a halogen atom).   The cationic fluorine-containing copolymer (A) is 70 to 90% by mass of the polymerized unit (a ′), 3 to 20% by mass of the polymerized unit (b ′), and of the polymerized unit (c ′). The oil-resistant processing agent of Claim 1 or 2 containing 7-25 mass%.   A method for producing oil-resistant paper, comprising an oil-resistant treatment step of adding the oil-resistant treatment agent according to any one of claims 1 to 3 to a constituent material of the paper.   In the oil-resistant treatment step, the composition (II) containing the amphoteric polyacrylamide resin (B) and the composition (I) containing the cationic fluorine-containing copolymer (A) are added to the pulp slurry. The manufacturing method of the oil-resistant paper of Claim 4 added in order.   Oil-resistant paper manufactured using the method for producing oil-resistant paper according to claim 4 or 5.