JP2005330623A - Oil-resistant paper material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new oil-resistant paper simply and inexpensively producible, exhibiting higher oil resistance while realizing a good flexural property when compared with an oil-resistant paper conventionally proposed and having high heat resistance, compared with a conventional oil-resistant paper. <P>SOLUTION: The oil-resistant paper is obtained by applying a silane-based coating solution forming a coating layer of siloxane bond by being cured and solidified by action of a catalyst and mainly containing one or more kinds of compound represented by formula (wherein R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>and R<SB>4</SB>are each a hydrogen atom or a 1-4C alkyl group may be same or different; n is 2-10) and a solution containing an organic polymer to a paper material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to cloth materials such as non-woven fabrics and cloths, and paper materials represented by Japanese paper and Western paper (hereinafter, these are comprehensively referred to as paper materials, and oil-resistant manufactured using these materials as materials. It is related to an oil-resistant paper imparted with a good oil resistance to an oil-resistant paper material).

  The oil-resistant paper has a function of preventing the hands and the like from being soiled with oil by the oil on the surface of the paper material penetrating into the inside and as a result being so-called back through. In recent years, westernization of eating habits has progressed, and for example, it has been widely used every day in daily life as food packaging materials and the like.

  For reference, only one example of oil-resistant paper found in daily life is illustrated as wrapping paper (boxes) such as fries and fried chicken in the fast food field, and donuts and cakes in the confectionery field. Oil-resistant paper is used for packaging of many foods such as paper (boxes), dairy products in the dairy product field, butters and ice cream wrapping paper (boxes), etc., in the snacks field, potato chips, etc. ing. In addition to such food packaging, for example, in the automobile industry, it is also used as a masking sheet for painting automobiles and the like, which has become indispensable for daily life. .

  By the way, since the paper material is generally made of entangled fibers with many voids, the oil adhering to the surface tends to penetrate into the inside by a capillary phenomenon. Therefore, the oil-resistant paper widely used in daily life as described above has been provided with oil resistance by forming a coating layer of a fluorine-based compound on the surface of the paper material until recently (hereinafter referred to as fluorine-based oil resistant paper). Paper). This is because the oil-resistant treatment agent comprising a fluorine-based compound can be added (internally added) at the same time when producing paper, so the production process of fluorine-based oil-resistant paper is simple, and as a result, oil-resistant paper can be produced at low cost. In addition to the above advantages, the fluorinated compound itself exhibits strong oil resistance, so that oil can be effectively prevented from penetrating into the fiber, and thus oil resistant paper having high oil resistance (fluorinated oil resistant paper) It is because there was also an advantage that it was possible to manufacture.

  As mentioned above, fluorinated oil-resistant paper can be manufactured at low cost and exhibits sufficiently high oil resistance in terms of performance. Also used in large quantities.

  However, recently, a safety test on fluorinated oil-resistant paper has been carried out. As a result, when fluorinated oil-resistant paper is heated to a high temperature (about 180 ° C), the generation of low-molecular evaporates is observed. Was discovered. As a result, with regard to fluorinated oil-resistant paper, the danger (toxicity) of this evaporate, that is, low-molecular substances, to the human body has been pointed out, and finally the production of fluorinated oil-resistant paper has been discontinued. .

  The production of fluorinated oil-resistant paper was discontinued, and the supply of heat-resistant paper that could be used as an alternative became urgent. As such an alternative oil-resistant paper, an oil-resistant paper coated with inexpensive and safe silicone oil was applied to the surface. It is proposed to use so-called laminated paper as oil-resistant paper.

  However, in oil-resistant paper with silicone oil applied to the surface, the silicone oil that gives oil resistance to the paper material is an oily compound, so even if it is applied to the paper material, it is not firmly fixed on the paper material. Therefore, in order to give sufficient oil resistance to the paper material, there is a problem that a large amount of the oil must be applied. This technical problem is nothing but the problem that the manufacturing cost of oil-resistant paper is high in terms of actual industrialization.

  In addition, since silicone oil is not fixed to the paper material, that is, transferability remains, if silicone oil is applied to the paper material and left for a long time, the oil will migrate and the surface of the paper material There was also a problem that the silicone oil film formed on the surface was uneven and the oil resistance became non-uniform.

  Laminated paper, on the other hand, exhibits sufficient oil resistance and can be manufactured at a low cost. Laminated paper is usually produced with a certain size and then cut appropriately according to the intended use. Therefore, when it is actually used as oil-resistant paper, the problem of oil permeating from the cut surface, and when disposing of used laminated paper, it must be separated from normal paper waste. There are still problems to be improved in terms of ease of use.

As another method, coating / impregnation of a resin having a high film forming ability is performed. Examples of the resin used include polyvinylidene chloride (PVDC), polyvinyl alcohol (PVA), acrylonitrile-butadiene rubber (NBR), carboxymethyl cellulose (CMC), methyl cellulose (MC), and the like. Among them, PVDC can form a highly crystalline coating film that cannot be obtained with other resins, and thus the coated paper exhibits excellent oil resistance. However, it is recognized that PVDC is a resin that is not suitable for mass use because it may cause harmful chlorides, particularly dioxins, during combustion, and thus has limitations in use.
Special Function Paper 2001, Paper Industry Times (issued in 2001)

  Other resins can be used for oil resistance without any environmental safety problems. However, basically, since a polymerized polymer is applied, there is a possibility that the polymer does not sufficiently enter the fiber of the paper.

  A paper material originally consists of a fiber part and a gap part between the fibers. When oil adheres to such a paper material, there are two types of permeation processes: the case where it penetrates from the gap between the fibers to the back side, and the case where it passes through the pores in the fiber by capillary action and permeates the back side. is there.

Since the organic polymer is a polymer, it plays a role of filling gaps between fibers. However, on the other hand, since it is a polymer, it has a property that it cannot sufficiently penetrate into the pores of the fiber. Therefore, when a paper material coated only with such an organic polymer is bent into a box shape, for example, oil may permeate from the bent portion, and as a result, sufficient oil resistance may not be exhibited.
JP 2004-19036 A

  Moreover, since such an organic polymer is made of an organic substance, it has a fatal defect that heat resistance is low. Recently, materials (containers) that can be easily cooked are preferred, and the good cooking characteristics in a microwave oven are an important factor for oil-resistant paper containers for cooking.

  As mentioned above, there is an urgent need to provide an alternative oil-resistant paper due to the discontinuation of the production of fluorinated oil-resistant paper, but the oil-resistant paper that has been proposed so far should be improved. The current situation is that there are challenges. Therefore, the object of the present invention can be easily and inexpensively manufactured. Further, when compared with the conventionally proposed oil-resistant paper, it achieves better oil resistance while achieving higher bending resistance, and moreover, An object of the present invention is to provide a new oil-resistant paper having higher heat resistance than oil-resistant paper.

（上記式１において、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ同一又は異なってもよい、水素原子又は炭素数１〜４のアルキル基であり、ｎ＝２〜１０である）
また第２の本願発明は、シラン系コート液が、式１で示される化合物の１種以上と下記式２（以下単に式２という）で示される化合物の１種以上とを主成分とすることを特徴とする耐油紙である。

（上記式２において、Ｒ_５、Ｒ_６及びＲ_７は、それぞれ同一又は異なっていてもよい、水素原子若しくは炭素数１〜１０のアルキル基又はアルケニル基であり、又は、Ｒ_５Ｏ、Ｒ_６Ｏ及びＲ_７ＯとＳｉとの結合はシロキサン結合であり、Ｒ_８は、その分子内にエポキシ基又はグリシジル基を含んでいてもよい、炭素数１〜１０のアルキル基若しくはアルケニル基、又はフェニル基である）
そして第３の本願発明は、前記第１又は第２の本願発明において、前記シラン系コート液を硬化・固化させる触媒として、加水分解可能な有機金属化合物を使用してシロキサン結合のコーティング層を形成することを特徴とする。
第４の本願発明は、第３の本願発明において、前記加水分解可能な有機金属化合物として、チタン、ジルコン、アルミ及びスズから成る群から選ばれる金属原子を含む一種以上の有機金属化合物を使用して、シロキサン結合のコーティング層を形成することを特徴とする。
第５の本願発明は、第４の本願発明において、前記加水分解可能な有機金属化合物として、テトラプロポキシチタニウム又はテトラブトキシチタニウムを使用して、シロキサン結合のコーティング層を形成することを特徴とする。
そして第６の本願発明は、有機高分子ポリマーが、アクリル系樹脂であることを特徴とする耐油紙；第７の本願発明は、有機高分子ポリマーが、ウレタン系樹脂であることを特徴とする耐油紙；第８の本願発明は、上記シラン系コート液と有機高分子ポリマーを含有する溶液を混合して塗布することを特徴とする耐油紙；第９の本願発明は、上記有機高分子ポリマーを含有する溶液を紙素材に塗布した後に、上記シラン系コート剤を塗布することを特徴とする耐油紙である。 As a result of intensive studies based on the present situation of such oil-resistant paper, the inventors of the present application have obtained sufficient oil resistance and bending characteristics by effectively filling both the inside and inter-fiber gaps of the paper material. In addition, the present invention was completed by finding that an oil-resistant paper having excellent heat resistance was obtained.
That is, the first invention of the present application is composed mainly of at least one compound represented by the following formula 1 (hereinafter simply referred to as formula 1), which is cured and solidified by the action of a catalyst to form a siloxane bond coating layer. The oil-resistant paper is obtained by applying a silane-based coating liquid and a solution containing an organic polymer to a paper material.

(In the above formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, which may be the same or different, and n = 2 to 10)
In the second invention of the present application, the silane-based coating liquid is mainly composed of at least one compound represented by the formula 1 and at least one compound represented by the following formula 2 (hereinafter simply referred to as the formula 2). Oil-resistant paper characterized by

(In the above formula 2, R ₅ , R ₆ and R ₇ are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkenyl group, which may be the same or different, or R ₅ O, R _6. The bond between O and R ₇ O and Si is a siloxane bond, and R ₈ is an alkyl or alkenyl group having 1 to 10 carbon atoms that may contain an epoxy group or a glycidyl group in its molecule, or phenyl. Base)
The third invention of the present application is the formation of a siloxane bond coating layer using a hydrolyzable organometallic compound as a catalyst for curing and solidifying the silane-based coating liquid in the first or second invention of the present application. It is characterized by doing.
According to a fourth invention of the present application, in the third invention of the present application, as the hydrolyzable organometallic compound, one or more organometallic compounds containing a metal atom selected from the group consisting of titanium, zircon, aluminum and tin are used. And forming a coating layer of siloxane bonds.
A fifth invention of the present application is characterized in that, in the fourth invention of the present application, a coating layer of siloxane bond is formed using tetrapropoxytitanium or tetrabutoxytitanium as the hydrolyzable organometallic compound.
The sixth invention of the present application is an oil-resistant paper characterized in that the organic polymer is an acrylic resin; the seventh invention of the present application is characterized in that the organic polymer is a urethane resin. Oil resistant paper; the eighth invention of the present application is a mixture of the above silane-based coating solution and a solution containing an organic polymer, and is applied; the ninth invention of the present application is the above organic polymer polymer The oil-containing paper is characterized in that the silane-based coating agent is applied after a solution containing is applied to a paper material.

According to the present invention, in the compound represented by Formula 1, one of the four substituents of the silicon atom cannot be hydrolyzed and is substituted with a substituent R ₄ that does not participate in the polycondensation between the compounds. By coating the paper material with a condensate of the thing, it penetrates into the inside of the fiber by capillary action and fills voids inside the fiber, thereby effectively preventing the penetration of oil into the inside of the fiber.

  Further, by using an organic polymer in combination, the gap between the fibers is filled and the oil penetration into the interior between the fibers is effectively prevented.

  By both of these effects, excellent oil resistance can be exhibited and oil resistance of the bent portion can be maintained.

Hereinafter, each invention of the present application will be described in detail.
As mentioned earlier, since the paper material has many voids in and between the fibers, the attached oil is easily penetrated into the fiber due to capillary action, and even between the fibers, the inside of the voids. The oil is easy to penetrate into

  Here, the capillary phenomenon is basically a phenomenon that occurs because there are many small spaces in the fiber. Therefore, an effective means for preventing the capillary phenomenon is to prevent the capillary phenomenon from occurring or to reduce the degree of the capillary phenomenon. For this purpose, the capillary phenomenon is utilized. The oil repellent material is allowed to penetrate into the paper material, and the permeated oil repellent material is bonded to the fiber and fixed, so that the permeation of the adhering oil into the paper material can be suppressed.

  On the other hand, the gap between fibers can be reduced by using so-called beating paper, but paper used for oil resistance is not always beating paper. Even if the gap is large, a treatment method having a so-called sealing effect is required.

  That is, the main constituent elements of the present invention are, first, to utilize the capillary phenomenon inside the fiber and to penetrate the silane coating agent having oil repellency, and secondly, to fill the gap between the fibers, The organic polymer polymer is filled between the fibers.

  Of the main components of the present invention, the first component is one in which one of the four substituents of the silicon atom is substituted with a non-hydrolyzable substituent as shown in Formula 1. A silane-based coating solution containing a compound containing as a repeating unit as a main component is applied to a paper material, penetrated into the fiber by capillary action, and further cured and solidified by the action of a catalyst to form a coating layer of siloxane bonds. By forming it inside, it prevents the oil from penetrating further inside the fiber, and the organic polymer polymer such as acrylic resin, which is the second component, is applied at the same time or in advance to make the gap between the fibers It solves the problems found in the prior art.

  The coating layer of the siloxane bond formed by curing and solidifying the silane-based coating liquid, which is the first component, has strong oil repellency, so that high oil resistance can be imparted to the inside of the fiber. The step of applying to the inside of the fiber and the step of curing and solidifying it by the action of a catalyst are very simple and can be carried out at a low cost as will be described later. In addition, the siloxane bond coating layer that is formed is firmly bonded and fixed inside the fiber, so there is no migration like silicone oil, and the coating layer formed inside the fiber is uneven. In other words, it is possible to achieve an effect that oil-resistant paper having excellent uniformity can be provided from the viewpoint of oil resistance.

  Furthermore, the coating layer of the siloxane bond based on the present invention retains flexibility, and the oil-resistant paper provided by the present invention bends almost in the same manner as a paper material that does not form a coating layer. In addition to being possible, after use, it can be disposed of in the same manner as ordinary paper waste. In addition, the oil-resistant paper of the present invention, unlike laminated paper, can be manufactured substantially only by the process of applying the coating liquid to the surface of the paper material, so it is cut into predetermined dimensions and shapes in advance. By applying a coating liquid to the cut surface of the paper material to form a coating layer, it is possible to prevent oil from penetrating from the cut surface.

  When applied to a paper material, the silane-based coating liquid containing the compound represented by Formula 1 as a main component penetrates into the fiber due to a capillary phenomenon. The compound represented by Formula 1 as the main component is a fiber in which the alkoxy group is hydrolyzed by moisture inside the fiber (surface) or moisture in the air (humidity), and a siloxane polymer is grown through a polycondensation reaction. Bind strongly with. The siloxane bond coating layer formed thereby suppresses capillary action inside the fiber and bonds strongly with the fiber. The siloxane bond is a complete inorganic bond, and exhibits properties opposite to those of oil, which is a typical organic substance, and therefore repels oil, ie exhibits oil repellency.

  Therefore, one of the roles of the compound represented by Formula 1 is to fill the voids inside the fiber, reduce capillary action, and coat the inside of the fiber with a siloxane-bonded polymer exhibiting oil repellency. By the action of both, high oil repellency is imparted to the paper material.

In addition, the compound represented by Formula 1 has only one strong siloxane bond between adjacent silicon atoms, but the unreacted side chain remains in a so-called “dangling” form. The coating layer itself is flexible, and as a result, even if such a coating layer is formed inside the fiber, the flexibility of the paper material can be maintained. That is, R ₄ in the compound represented by the formula 1 is not hydrolyzed even if the compound represented by the formula 1 undergoes a subsequent hydrolysis / polycondensation reaction, so that the coating layer formed thereby has flexibility. Will give.

  In the present invention, a coating liquid mainly composed of one or more compounds represented by Formula 1 is applied to a paper material such as paper or nonwoven fabric, and this is cured and solidified by the action of a catalyst. The compound represented by 1 can be obtained by condensing a monomer (for example, methyltrimethoxysilane). The repetition of the main chain is n = 2-10, preferably n = 2-8, particularly preferably n = 4-5 as detailed in the examples. When n = 1, that is, a monomer is used, it takes time to polymerize, and it is difficult to form a coating layer having sufficient strength in a short time. In addition, since the monomer is highly volatile, unreacted components are volatilized and the solid content may not be constant, which is not suitable. On the other hand, when n = 11 or more, conversely, when applied to a paper material, the number of alkoxy groups for polymerizing inside the paper material is insufficient, and a coating layer having sufficient strength is formed. It is difficult to make it. Further, when the polymer is n = 11 or more, the molecular chain becomes large, and the polymer does not reach the depth of the pores inside the fiber sufficiently, which is not preferable.

  In general, when a condensate such as a compound represented by Formula 1 is synthesized from monomers, it is technically impossible to accurately control the degree of polymerization. Therefore, in the present invention, n = 2 to 10, preferably n = 2 to 8, particularly preferably n = 4 to 5, and the meaning that the main component is a compound represented by Formula 1 is from the distribution of the degree of polymerization. As seen, each compound mainly includes a compound represented by Formula 1 where n = 2 to 10, n = 2 to 8, or n = 4 to 5, for example, n is 11 or more May be included as long as it is not the main.

  Specific examples of the compound represented by Formula 1 include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane. Examples thereof include condensates such as ethoxysilane, methyltripropoxysilane, and ethyltripropoxysilane. The compound represented by Formula 1 may be a product obtained by condensing only one type of the above exemplified monomers, or a product obtained by condensing two or more types of the above exemplified monomers. Good.

  In the present invention, in addition to one or more compounds represented by Formula 1, a coating solution containing one or more compounds represented by Formula 2 as a main component can also be used. The compound represented by Formula 2 is a compound in which three of the four substituents are hydrolyzable substituents and the remaining one is a non-hydrolyzable substituent. Therefore, by using the compound represented by Formula 1 together with the compound represented by Formula 1 as a main component, the flexibility of the oil-resistant paper is improved, or the properties such as the flexibility of the compound represented by Formula 2 are improved. It can be newly added to paper.

  Specific examples of the compound represented by Formula 2 include vinyltrimethoxysilane, phenyltrimethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, β- (3,4 Epoxycyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, γ- (methacryloxypropyl) triethoxysilane, γ-glycidoxypropyltriethoxysilane, aminopropyltriethoxysilane , Vinyltris (β-methoxyethoxy) silane and the like, and condensates of about 2 to 10 molecules thereof.

  The compound represented by Formula 2 may be two or more of such monomers. Further, when two or more molecules of a condensate are used as the compound represented by Formula 2, two or more of these monomers may be condensed.

  When the compound represented by Formula 2 is added, the compound is preferably added in a range not exceeding 50% as a whole with respect to the compound represented by Formula 1. When the total addition amount of both exceeds 50%, when the coating solution is applied to a paper material, it does not bond well with the compound represented by Formula 1 as the main component, and the coating of the siloxane bond formed This is because the strength of the layer may be insufficient. Therefore, when the compound represented by Formula 2 is actually added, it is preferable to minimize the addition assuming that the strength of the coating layer is lowered depending on the addition amount.

The primary role of the non-hydrolyzable substituent (R ₈ ) in the compound represented by Formula 2 is to provide flexibility to the coating layer of the siloxane bond. Since it is an organic substituent, it has an effect that water repellency can be imparted to the coating layer (oil-resistant paper) at the same time. In general, the organic substituent increases as the carbon number increases, that is, the organic property, that is, the water repellency increases. However, if the carbon number is too large, the coating film is distorted due to steric hindrance, and the film strength is reduced. Caution must be taken.

  On the other hand, siloxane bonds with strong heat resistance and wear resistance are also so-called “hard” bonds. Because of this “hardness,” when applied to a paper material such as paper, the material can be given abrasion resistance. However, the paper material such as paper is characterized by its flexibility, Is sometimes required to be as flexible as the material, such as paper.

Conventionally known sol-gel coating solutions use tetraalkoxysilane (Si (OR) ₄ ) or oligomers as starting materials. When this is completely hydrolyzed (reaction formulas (1) to (3) described below) to form a coating layer, all four bonds of silicon atoms form a network of hard siloxane bonds. Is hard like ceramic, but it becomes a brittle coating layer lacking in flexibility, so it is practically impossible to produce oil-resistant paper making use of flexibility such as paper. However, the present invention solves this problem by using, as a main component of the coating liquid, a compound represented by Formula 1 in which one of the four substituents of the silicon atom is not hydrolyzed. Moreover, in this invention, it becomes possible to increase a softness | flexibility etc. further by adding the compound shown by Formula 2 which has one substituent which is not hydrolyzed to a coating liquid.

  In order to provide an oil-resistant paper that requires not only sufficient oil resistance and flexibility but also abrasion resistance, the compound represented by Formula 1 alone may be insufficient. In this case, a tetraalkoxysilane represented by the following formula 3 (hereinafter simply referred to as formula 3) or an oligomer thereof is added to the compound represented by formula 1 to obtain a coating solution for improving wear resistance. be able to.

Si (OR ₉ ) ₄
(Here, R ₉ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, which may be the same or different.)

  Thus, the compound used in the first component among the main components of the invention of the present application requires the compound represented by Formula 1 and depends on the degree of flexibility and abrasion resistance required for the paper material. By adding the compound represented by Formula 2 and / or Formula 3 as necessary, the paper material is required not only for oil repellency and oil resistance but also for wear resistance, water repellency, flexibility, and the like. Practical performance can be added / improved.

  As a catalyst for curing and solidifying the compound represented by Formula 1, a commonly used catalyst can be used without any particular limitation. For example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, formic acid or acetic acid can be exemplified as acid catalysts. Examples of the base catalyst include ammonia, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, ethanolamine, diethanolamine, and triethanolamine. When these ordinary catalysts are used, reaction water is allowed to coexist in order to cure and solidify the compound represented by Formula 1.

  More specifically, the coating liquid as the first component provided by the present invention includes the compound represented by the formula 1, which is the main component, a catalyst, and reaction water. However, among the main constituent elements of the present invention, the organic polymer used as the second constituent element is generally not mixed with water and is often used in an organic solvent. Therefore, it is desired that the silane-based coating liquid used as the first main component of the present invention does not contain water. At the same time, the use of acid catalysts is limited because paper materials often deteriorate when acids are used.

  In order to avoid such a limitation, it is preferable to use a hydrolyzable organometallic compound instead of the usual catalyst as exemplified above. If a hydrolyzable organometallic compound is used, it is not necessary for the acid catalyst and the reaction water to coexist in the silane-based coating liquid, and a coating liquid that is uniform and has no deterioration of the paper material can be obtained.

  Examples of the organometallic compound preferably used in the present invention include those containing, for example, titanium, zircon, aluminum, or tin as a metal atom. More specifically, tetrapropoxy titanate, tetrabutoxy titanate, tetrapropoxy zirconate, tetrabutoxy zirconate, tripropoxy aluminate, aluminum acetylacetonate and the like can be exemplified.

  When a hydrolyzable organometallic compound is mixed with the compound represented by Formula 1 to form a coating solution and applied to a paper material, it absorbs moisture inside the paper material and on the surface or moisture (humidity) in the air, The compound hydrolyzes itself, but at this time, the compound represented by Formula 1 and the organometallic compound form a network, and the compound represented by Formula 1 is cured and solidified.

  In addition, an organic solvent can be added to the silane-based coating liquid of the present invention in order to uniformly mix the compound represented by the formula 1, the catalyst, and optionally required reaction water. Examples of the organic solvent used for this purpose include alcohols. More specifically, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol and the like can be exemplified. Also, the viscosity and drying speed of the coating solution can be adjusted by controlling the amount of addition.

  For the purpose of such adjustment, in particular glycols such as ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, methoxyethanol, propoxyethanol, butoxyethanol, methoxypropanol, ethoxypropanol, propoxypropanol Alternatively, it is preferable to use an organic solvent having a high viscosity or boiling point, such as cellosolves such as butoxypropanol, alone or in combination. Of course, the alcohols may be added simultaneously with at least one organic solvent having a high viscosity or boiling point. When the purpose is to adjust the viscosity and drying speed of the coating solution, the same effect can be achieved not only by the organic solvent but also by a surfactant.

  The solvent used in the silane-based coating liquid of the present invention is not necessarily limited to the above alcohol-based solvent in relation to the solvent used in the organic polymer polymer-based coating liquid used during coating. In that case, toluene, ethyl acetate or the like can also be used.

  Next, a solution containing an organic polymer system (hereinafter referred to as an organic polymer solution), which is the second component of the present invention, will be described. The organic polymer polymer applied by the organic polymer solution fills the voids between the fibers and prevents oil from penetrating through the fibers. Although the high molecular polymer used for this purpose is usually used for oil-resistant paper, it can be used without any particular limitation. However, as described above, since PVDC contains chlorine, This is not preferred because it causes problems during combustion.

  In general, acrylic resin, urethane resin, PVA, NBR, CMC, MC and the like can be used as the organic polymer polymer which is the second constituent element of the present invention. Among these, acrylic resin and urethane resin are particularly preferable. As used herein, the acrylic resin refers to a synthetic resin mainly composed of a polymer of acrylic acid, methacrylic acid, and derivatives thereof, and actually refers to a polymer such as an acrylic ester, methacrylic ester, or acrylonitrile. These may be a copolymer with vinyl acetate, styrene or the like.

  The urethane resin is a chain polymer formed by a reaction between an aliphatic polyisocyanate and tetramethylene glycol, and a commonly used one can be used without any particular limitation. Thermosetting or thermosetting may be used, but thermosetting is preferable in consideration of use in heat-resistant applications such as a microwave oven.

  The method of coating a paper material with the silane-based coating liquid that is the first component of the present invention and the organic polymer solution that is the second component is to uniformly mix the two solutions (so-called In the method of coating (one-component type), the organic polymer solution may be applied first, and then the silane-based coating solution may be applied.

  When a uniformly mixed solution is applied, the silane compound represented by Formula 1 is a low-molecular oligomer having an average degree of polymerization of 2 to 10, and thus preferentially penetrates into the fiber by capillary action. On the other hand, the organic polymer is a polymer with a much higher degree of polymerization, so it cannot fully penetrate into the pores inside the fiber, but instead stays in the voids between the fibers. Fulfill. From this, it is preferable to apply the two liquids as a mixed liquid.

  It is also possible to apply the organic polymer polymer first and then apply the silane compound represented by Formula 1. In this method, since the high molecular polymer cannot sufficiently penetrate into the inside of the fiber, the silane compound applied later penetrates into the portion, and as a result, oil resistance comparable to that of the one-pack type is obtained. .

  However, on the other hand, when the silane-based coating liquid is applied first, the silane compound is applied not only inside the fibers but also between the fibers, so that there is a shortage of silane compounds that should be sufficiently distributed inside the fibers. Therefore, sufficient oil resistance may not be obtained. Therefore, it is desirable to apply a silane liquid after applying a one-pack type or organic polymer solution.

  In order to produce the oil-resistant paper of the present invention, first, an arbitrary paper material is cut and processed into an arbitrary size and shape, and the coating liquid (silane-based coating liquid and organic polymer polymer) used in the present invention described above is then used. Apply the solution. The specific application method is not particularly limited. For example, it can be performed by immersing the paper material in the coating liquid, applying the coating liquid to the paper material, or spraying the coating liquid onto the paper material. It is.

  In the present invention, for example, those obtained by drying bark fibers, dried handmade high-grade Japanese paper, machine-made ordinary Japanese paper, Western paper or Yuzen paper, non-woven fibers, ordinary cloths, etc. The material can be manufactured. These paper materials can usually be used without limitation by changing the type and concentration of the coating liquid.

  As described above, when the coating liquid is applied to the paper material in a one-pack type or a two-pack type, the compound represented by the formula 1 is hydrolyzed and undergoes the reactions shown in the following reaction formulas (1) to (3) to obtain siloxane. A bond (Si—O—Si) is generated.

  Since the siloxane bond (Si—O—Si) generated in this way grows from the inside of the fiber, it becomes possible to fill fine pores inside the fiber and reduce the capillary phenomenon. At the same time, the entanglement due to the growth of siloxane bonds from the inside of the fiber contributes to the improvement of the adhesion strength with the fiber.

  When the coating liquid of the present invention contains the above-described organometallic compound (for example, tetrabutoxy titanium, etc.) as a catalyst, the reaction formulas (1) to (3) above can be used even if the coating liquid does not contain reaction water. Although the reaction proceeds, the reaction in this case is as shown in the following reaction formulas (4) and (5) in detail.

  As described above, by introducing the Ti—O bond into the coating layer, the heat resistance and wear resistance of the paper material can be improved as compared with the coating layer having only the siloxane bond. As described above, when an organometallic compound is used as a catalyst, not only the reaction water and the acid catalyst need not coexist, but also the heat resistance and abrasion resistance of the coating layer are further improved, and as a result, the oil-resistant paper material. The heat resistance and wear resistance of can be made even stronger.

  Conventionally used organic polymer oil proofing agents such as acrylic resins show a certain level of oil resistance when uniformly coated on the surface of a paper material. However, there has been a problem of permeation of oil from the bent portion. This is a phenomenon that occurs because the inside of the fiber is deformed during bending. The organic polymer resin plays a role of filling between the fibers, but does not sufficiently penetrate into the inside of the fibers. Therefore, along with the deformation of the fiber part at the time of bending, the oil component penetrates into the inside from the deformed part, and the oil resistance decreases. For this reason, when only the organic polymer-based oil proofing agent is used, there is a problem that the oil resistance is lowered when the oil-proof paper is used in a box shape.

  However, the oil-resistant paper of the present invention has a low molecular weight alkoxysilane that penetrates into the fiber by capillary action, grows as a polymer from the inside, and is coated on each fiber. Less deformation of the part. Further, even if a space is generated inside the fiber due to deformation, the occurrence of capillary action at that portion is suppressed, and as a result, permeation of oil from the bent portion can be prevented.

  Hereinafter, although this invention is demonstrated in detail based on an Example, an Example is an example to the last, Comprising: This invention is not limited.

Example 1
83 g of methyltrimethoxysilane condensate (MTM) (average polymerization degree n = 4 to 5) (compound represented by formula 1) is dissolved in 180 g of isopropyl alcohol, and titanium tetrabutoxide (hydrolyzable organometallic compound) is dissolved therein. 6.2 g was added and sufficiently stirred to prepare a silane-based coating solution.

  As an acrylic resin solution, an isopropyl alcohol solution containing approximately 20% of an acrylic (methacrylic acid) ester copolymer (manufactured by Kyoyo Chemical Industry Co., Ltd.) was used, and 100 g of the silane-based coating solution and 200 g of the acrylic resin solution were uniformly mixed to form a coating solution. did.

Next, bleached kraft paper (manufactured by Chuetsu Pulp Co., Ltd., basis weight 70 g / m ² ) is prepared as a paper material, and is applied at a coating amount (weight before drying) of 6.8 g / m ² using a bar coater. The coating solution was applied and dried at room temperature for 10 minutes to evaporate the alcohol, and then heated in a dryer at 120 ° C. for 10 minutes to produce oil-resistant paper.

  The oil repellency test for the oil-resistant paper obtained in this manner was conducted using the JAPAN TAPPI paper pulp test method NO. 41: 2000, “Paper and paperboard—oil repellency test method—kit value”. In conducting the oil repellency test, first, cast oil, toluene, and heptane were mixed at a predetermined ratio to prepare test solutions of kit numbers 1 to 12. Next, 5 or more oil-resistant paper cut into a size of about 50 mm × 50 mm was prepared as a test piece, and an oil repellency test was performed. In the oil repellency test of the bent portion, the paper piece was bent at 90 degrees, and the test was performed at that portion.

Comparative Example 1
A bleached kraft paper having substantially the same dimensions without applying the silane-based coating solution and applying only the acrylic resin solution (described above) was prepared, and the same oil repellency test as described above was performed. The results are shown in Table 2.

Examples 2-6
An oil-resistant paper was produced in the same manner as in Example 1 except that the paper material shown in Table 1 was used, and an oil resistance test was conducted in the same manner. The results are shown in Table 1.

Comparative Examples 2-6
Prepare the paper material used in Examples 2 to 6 having substantially the same dimensions without applying the silane-based coating solution and applying only the acrylic resin solution (described above), and the same oil repellency test as described above. Carried out. The results are shown in Table 2.

Example 7
Bleached kraft paper (manufactured by Chuetsu Pulp Co., Ltd., basis weight 70 g / m ² ) is prepared as a paper material, and the acrylic resin is applied at a coating amount (weight before drying) of 6.8 g / m ² using a bar coater. The solution was applied and dried at room temperature for 10 minutes to evaporate the alcohol, and then heated in a dryer at 105 ° C. for 10 minutes. Thereafter, a solution obtained by diluting the silane-based coating solution twice with isopropyl alcohol was applied using a bar coater at an application amount (weight before drying) of 6.8 g / m ^2. It was dried for 1 minute to evaporate the alcohol, and further heated in a dryer at 120 ° C. for 10 minutes to produce an oil-resistant paper. Thereafter, an oil resistance test was conducted in the same manner as in Example 1. The results are shown in Table 1.

Examples 8-12
An oil-resistant paper was produced in the same manner as in Example 7 except that the paper material shown in Table 1 was used, and an oil resistance test was conducted in the same manner. The results are shown in Table 1.

Example 13
The above silane-based coating solution was prepared by adding 63 g of methyltrimethoxysilane condensate (MTM) (average polymerization degree 4 to 5) (compound represented by formula 1) and γ-glycidoxypropyltrimethoxysilane (expressed by formula 2). Compound) 20 g was dissolved in isopropyl alcohol 180 g, and titanium tetrabutoxide (hydrolyzable organometallic compound) 6.2 g was added thereto and stirred sufficiently. In the same manner, an oil resistance test was conducted. The results are shown in Table 1.

Example 14
An oil-resistant paper was produced in the same manner as in Example 7 except that a urethane resin solution (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., aqueous solution with a solid content of about 20%) was used instead of the acrylic resin solution. Carried out. The results are shown in Table 1.

  As is apparent from Tables 1 and 2, the oil-resistant paper coated with an acrylic resin conventionally used as an oil-resistant agent for comparison has an oil repellency (KIT value) of 6 or less. there were. On the other hand, in the oil-resistant paper of the present invention, the kit values were all 10 or more, and about twice the oil resistance was recognized.

  Further, the oil resistance of the bent portion is slightly inferior to that of the smooth portion, but still retains a KIT value of 8 or more, indicating sufficient oil resistance.

  The oil-resistant paper of the present invention is manufactured from a material safe for the human body and the environment. When compared with the oil-resistant paper proposed so far, the oil-resistant paper achieves good bending characteristics (flexibility) and higher oil resistance. In addition, it exhibits high heat resistance compared to conventional oil-resistant paper. Therefore, it is very useful as an oil-resistant paper container for cooking that requires high oil resistance, heat resistance and safety.

  Moreover, since the oil-resistant paper of the present invention can be easily disposed of without adversely affecting the human body and the environment, it can be used for various purposes in daily life.

  Since the oil-resistant paper of the present invention can be produced simply and inexpensively, it can be industrially produced very advantageously.

Claims (9)

A silane-based coating liquid mainly composed of one or more compounds represented by the following formula 1, which is cured and solidified by the action of a catalyst to form a siloxane bond coating layer, and a solution containing an organic polymer Is an oil-resistant paper made by applying to a paper material.

(In the above formula 1, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, each being a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n = 2 to 10) 2. The oil-resistant paper according to claim 1, wherein the silane-based coating liquid contains, as a main component, one or more compounds represented by Formula 1 and one or more compounds represented by Formula 2 below.

(In the above formula 2, R ₅ , R ₆ and R ₇ are each a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an alkenyl group which may be the same or different, or R ₅ O, R The bond between ₆ O and R ₇ O and Si is a siloxane bond, and R ₈ is an alkyl group or alkenyl group having 1 to 10 carbon atoms, which may contain an epoxy group or a glycidyl group in the molecule, Or a phenyl group.) The oil-resistant paper according to claim 1 or 2, wherein a hydrolyzable organometallic compound is used as a catalyst for curing and solidifying the silane-based coating liquid to form a siloxane bond coating layer. . A siloxane bond coating layer is formed using one or more organometallic compounds containing a metal atom selected from the group consisting of titanium, zircon, aluminum and tin as the hydrolyzable organometallic compound. The oil-resistant paper according to claim 3. 5. The oil-resistant paper according to claim 4, wherein a coating layer of siloxane bond is formed using tetrapropoxytitanium or tetrabutoxytitanium as the hydrolyzable organometallic compound. The oil-resistant paper according to claim 1, wherein the organic polymer is an acrylic resin. The oil-resistant paper according to claim 1, wherein the organic polymer is a urethane resin. The oil-resistant paper according to claim 1, wherein the silane-based coating liquid and a solution containing an organic polymer are mixed and applied. The oil-resistant paper according to claim 1, wherein the silane-based coating liquid is applied after the solution containing the organic polymer is applied to a paper material.