JP6397276B2 - Oil resistant agent and oil resistant paper - Google Patents

Description

  The present invention relates to an oil resistant agent and an oil resistant paper obtained using the same.

  Oil-resistant paper having oil resistance is widely used for food, building materials, industrial materials and the like. In food applications, it is used in food containers or sheets such as fried chicken, croquettes, tempura, and fries that use edible oil, and food containers or sheets that use dairy products and mayonnaise. Oil-resistant paper used in food containers up to now is often used for film-laminated paper due to the problem of harmfulness of oil-resistant paper using fluororesin. However, although film laminated paper has good oil resistance, it has been pointed out that it is difficult to use because of problems of waste separation and curling during use. For this reason, as known in Patent Document 1, there are some coated with a silicone oil coating agent, but they are oily and have a problem of transfer to foods.

  For building materials, there is a demand for decorative paper having oil resistance for decorative plywood used around kitchens. As a decorative paper having oil resistance, a stain-resistant decorative board is known in which a coating material obtained by curing a fluororesin with an isocyanate curing agent is applied to the surface of a building material (for example, Patent Document 2). However, when using a coating film obtained by curing a fluororesin with an isocyanate curing agent, there are disadvantages in terms of cost, and the fluororesin generates hydrogen fluoride and low molecular weight fluorine compounds during incineration, causing harmful air pollution, There is also the possibility of destroying the ozone layer. Therefore, the use of such a fluororesin has been prohibited in recent years. There is also a method to prevent the penetration of oil into the base paper by increasing the amount of printing ink applied and further printing the top coat several times, but the desired oil resistance is maintained unless the amount of printing ink applied is increased. This is difficult and costly.

  On the other hand, it is known in Patent Documents 3 and 4 to use a siloxane-based oil-resistant paper different from the fluororesin-based and silicone oil-based materials used for conventional oil-resistant paper. This siloxane-based oil-resistant paper uses a silane-based coating liquid mainly composed of a methyltrimethoxysilane condensate having an average polymerization degree of 3 to 4, and is cured by the action of tetrapropoxy titanium after being applied to the paper material. An oil-resistant paper having 10 times oil repellency as compared with a paper material is produced by solidifying and forming a siloxane bond coating layer on the surface. However, the oil repellency of the siloxane-based coating agent is due to silanol groups in which alkoxy groups are hydrolyzed, and there is a problem that oil resistance is low because there is no silanol groups just by crosslinking with methyltrimethoxysilane and tetrapropoxytitanium. In addition, when methyltrimethoxysilane is the main component and one of the four functional groups is an alkyl group, the coating layer itself after crosslinking is three-dimensionally crosslinked, so that flexibility cannot be obtained. There is a problem that the oleophilicity is increased, so that the oil resistance cannot be sufficiently exhibited.

Japanese Patent No. 4229850 JP-A-10-000428 JP 2005-36322 A JP 2005-330623 A

  An object of the present invention is to provide an oil resistant paper containing polysiloxane and an oil resistant paper using the oil resistant agent for obtaining an oil resistant paper having little influence on the environment and excellent in blocking resistance, oil resistance and heat resistance. It is intended.

As a result of diligent investigations, the present inventors have found that the above object can be achieved by using an oil-resistant agent containing a specific polysiloxane having a large number of silanol groups having oil resistance, and complete the present invention. It came to.
That is, the present invention relates to the following [1] to [7].

[1] An oilproofing agent containing polysiloxane represented by the following general formula (1).
[In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are any one selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and R ₁ , R ₂ , R ₃ and A part of R ₄ is a hydrogen atom. n is an average degree of polymerization and is 4-20. ]
[2] The oilproof agent according to [1], wherein in the general formula (1), the alkyl group having 1 to 4 carbon atoms is at least one selected from a methyl group or an ethyl group.
[3] The oil resistance according to the above [1] or [2], wherein the ratio of silanol groups to the total amount of silanol groups and alkoxy groups in the polysiloxane represented by the general formula (1) is 30 to 50 mol%. Agent.
[4] The polysiloxane represented by the general formula (1) is a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having an average polymerization degree of 4 to 10 and having 1 to 4 carbon atoms. [1] to [1] above, which is obtained by hydrolyzing a silicate having 0.2 to 0.5 mol of water with respect to 1 mol of an alkoxy group in an alcohol and then polycondensation. [3] The oil resistant agent according to any one of [3].
[5] A part of the polysiloxane represented by the general formula (1) is modified with 0.01 mol to 0.1 mol of a silane coupling agent with respect to 1 mol of the alkoxy group in the polysiloxane. The oil resistant agent according to any one of [1] to [4].
[6] The oilproof agent according to any one of [1] to [5], wherein the polysiloxane is contained in an amount of 15 to 80% by mass.
[7] An oil resistant paper obtained by applying the oil resistant agent according to any one of [1] to [6].

  The oil-resistant agent of the present invention can provide an oil-resistant paper that has little influence on the environment and is excellent in blocking resistance, oil resistance, and heat resistance.

It is a schematic sectional drawing which shows an example of the oil resistant paper using the oil resistant agent of this invention. It is a schematic sectional drawing which shows an example of the oil resistant paper using the oil resistant agent of this invention. It is an infrared absorption spectrum figure of the methyl silicate which does not contain Si-OH group. It is an infrared absorption spectrum figure of the methyl silicate containing a Si-OH group.

[Oil-proofing agent]
<Polysiloxane>
The oilproofing agent of the present invention contains a polysiloxane represented by the following general formula (1).

In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are any one selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and R ₁ , R ₂ , R ₃ and A part of R ₄ is a hydrogen atom. n is an average degree of polymerization and is 4-20.

  In the polysiloxane of the general formula (1), silicon atoms and silicon atoms are bonded with oxygen atoms, and other silicon atoms are bonded with silanol groups (hydroxy groups) and carbon atoms of 1 to 4. It is a bond with the alkoxy group. Examples of the alkyl group having 1 to 4 carbon atoms forming the alkoxy group having 1 to 4 carbon atoms include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and tert-butyl group. However, a methyl group and an ethyl group are preferable from the viewpoint of oil resistance. N which shows an average degree of polymerization is 4-20. When n is less than 4, the oil resistance is lowered, which is not preferable. Also. When n exceeds 20, when it is used as an oil resistant agent, it is difficult to apply a uniform thickness, which is not preferable. The average degree of polymerization n is preferably 8-14.

  The polysiloxane represented by the general formula (1) has a silanol group derived from a hydrogen atom and an alkoxy group derived from an alkyl group having 1 to 4 carbon atoms, but the total amount of the silanol group and the alkoxy group in the polysiloxane. It is preferable that the ratio of the silanol group with respect to is 30-50 mol%. If the ratio of silanol groups is within this range, the resulting polysiloxane will not gel, so it can be easily applied to paper when used as an oil resistant agent, and good oil resistance when used as oil resistant paper. Sex is obtained. The structure of the polysiloxane represented by the general formula (1) can have various structures such as linear, branched, and network.

  In order to produce an oilproofing agent containing the polysiloxane represented by the general formula (1), a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms, or an average degree of polymerization of 4 to 10 and 1 to 1 carbon atoms. A silicate having 4 alkoxy groups can be obtained by hydrolysis in alcohol using water in an amount of 0.2 to 0.5 mol per mol of alkoxy group contained, and then polycondensation. . Examples of the tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Among these, it is preferable to use tetramethoxysilane and tetraethoxysilane. Examples of the silicate having an average polymerization degree of 4 to 10 and having an alkoxy group having 1 to 4 carbon atoms include the condensates of tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms. Specifically, methyl silicate, ethyl silicate, pyropyrusilicate, butyl silicate and the like having a degree of polymerization of 4 to 10 can be mentioned. When a silicate having an average degree of polymerization of 4 to 10 and having an alkoxy group having 1 to 4 carbon atoms is used, the alkoxy group having 1 to 4 carbon atoms is preferably a methoxy group or an ethoxy group.

When hydrolyzing the above tetraalkoxysilane or silicate in alcohol, 0.1 to 0.7 mol of water is usually used per 1 mol of the alkoxy group contained, but it is used for hydrolysis. The amount of water used is extremely important because it affects the content of silanol groups and thus storage stability. If the amount of water used for hydrolysis is 0.1 to 0.7 moles per mole of alkoxy groups, the silanol groups will be in an appropriate amount and there is no risk of three-dimensional crosslinking or gelation. An oil-resistant agent that can maintain storage stability and has good oil resistance can be obtained. The amount of water used for the hydrolysis is preferably 0.2 to 0.5 mol with respect to 1 mol of the alkoxy group.
The hydrolysis is preferably performed in the presence of a catalyst. The catalyst is not particularly limited, but organic acids such as p-toluenesulfonic acid, p-phenolsulfonic acid, naphthalenesulfonic acid, maleic acid and acetic acid, inorganic acids such as hydrochloric acid, nitric acid and phosphoric acid, and the like A salt can be used in combination as appropriate. As a usage-amount of a catalyst, 0.01-0.1 mol can be normally used with respect to 1 mol of usage-amounts of water.

  This hydrolysis is performed in a solvent, and an alcohol is preferably used as the solvent. As alcohol used, C1-C5 alcohols, such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, are normally used, Preferably C1-C3 alcohol is used. By using these alcohols, the resulting hydrolyzate can be formed as fine particles, and the properties of the cured coating film obtained after coating as an oil resistance agent will be excellent. In particular, an alcohol having the same carbon number as the alkoxy group having 1 to 3 carbon atoms is preferably used, and methanol and ethanol are preferably used. In order to adjust the drying property, a small amount of cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methylpropyl cellosolve, ethylpropyl cellosolve, butylpropyl cellosolve may be used in combination. The amount of the solvent used is usually in the range of 50 to 200 parts by mass with respect to 100 parts by mass of tetraalkoxysilane or silicate.

  In the above hydrolysis, the tetraalkoxysilane or silicate and alcohol are introduced into a reactor equipped with a stirrer purged with an inert gas such as nitrogen and stirred at room temperature, and then the acid catalyst. It is possible to dilute the water and water with the rule used as needed, and to introduce the reaction into the reactor little by little under stirring, thereby carrying out the hydrolysis reaction. During the hydrolysis reaction, the reaction temperature in the reactor gradually rises, and when the hydrolysis reaction ends, the increase in the reaction temperature stops, so that it can be used as a measure for the end of the hydrolysis reaction. Usually, although the reaction time of a hydrolysis reaction changes with the usage-amounts and kind of raw material, it is about 10 minutes-2 hours. By performing this hydrolysis reaction, a part of the alkoxy group in the tetraalkoxysilane or silicate can be converted into a silanol group.

  After completion of the hydrolysis, the reaction temperature in the reactor stops increasing and gradually decreases, so that the polycondensation can be performed by continuing the stirring as it is. Polycondensation is the reaction between an alkoxysilane having a silanol group or a silanol group in a silicate having a silanol group and an alkoxy group, a reaction between alkoxy groups in an alkoxysilane having a silanol group, and an alkoxy in a silicate having a silanol group. Si—O—Si is generated by reaction between the groups and the like, and polycondensation is performed. The polycondensation time is usually about 1 to 10 hours. If the polycondensation time is too long, the average degree of polymerization increases and exceeds 20, so care must be taken. Therefore, when the predetermined polycondensation time is completed, it is preferable to cool the obtained reaction mixture to a temperature not higher than room temperature.

  The reaction mixture obtained after the polycondensation contains the polysiloxane represented by the general formula (1). The oil-proofing agent of the present invention may be used as the oil-proofing agent as it is after the reaction mixture obtained after polycondensation, or if necessary, removing the organic solvent from the reaction mixture, or adding an organic solvent, Can be used as an oil resistant agent.

<Silane coupling agent-modified polysiloxane>
The oilproofing agent of the present invention is a polysiloxane (also referred to as a silane coupling agent-modified polysiloxane) obtained by reacting the polysiloxane represented by the general formula (1) described above with a silane coupling agent and modifying it with the silane coupling agent. ) And containing polysiloxane modified with this silane coupling agent can be used as an oil resistance agent. This silane coupling agent-modified polysiloxane can prevent gelation of the polycondensation product by partially modifying a silanol group with a silane coupling agent. As a method for partially modifying a silanol group, a ratio of 0.01 mol to 0.1 mol of a silane coupling agent with respect to 1 mol of an alkoxy group in the polysiloxane represented by the general formula (1) It can be denatured by addition and reaction by further mixing and stirring. The stirring time may be about 30 minutes to 2 hours.

  Silane coupling agents The silane coupling agents used in the production of modified polysiloxanes include glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, styrylmethoxysilane, methacryloxypropylmethyldimethoxysilane, methacrylate. Alkoxy such as loxypropyltriethoxysilane, acryloxytrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, aminopropyltrimethoxysilane, ureidopropyltriethoxysilane, chloropropyltrimethoxysilane, mercaptopropyldimethoxysilane The silane coupling agent which has group can be mentioned, These silane coupling agents can be used individually or in combination of several types.

  The oil proofing agent of the present invention may contain a hardening accelerator, a thickener, a surfactant, other additives, and the like as necessary.

[Oil-resistant paper]
Various paper base materials can be used for the oilproofing agent of the present invention thus obtained. As these paper bases, for example, wrapping paper such as kraft paper, pure white roll paper, thin-mouth imitation paper, base paper for decorative board, wallpaper base paper, food container base paper and other industrial paper, thin paper printing paper, gravure paper, etc. Examples include paper. These paper base materials can be coated with various coating methods such as a gravure coater, a bar coater, a roll coater, a flow coater and the like to obtain an oil resistant paper. Moreover, the oilproofing agent of the present invention can be impregnated in various paper substrates by spraying or dipping depending on the case. The coating amount is 1 to 10 g / m ² , preferably 3 to 5 g / m ^{2 in} terms of dry mass (solid content mass) of the oil resistant agent. When the coating amount is 1 g / m ² or more, paper fibers can be sufficiently covered, and sufficient oil resistance can be obtained. In addition, when the coating amount is 10 g / m ² or less, a sufficient dry coating film can be obtained during coating, and the possibility of blocking and unwinding is reduced. Furthermore, the possibility of losing the flexibility of the paper is reduced. The drying temperature after coating is usually 70 ° C. to 200 ° C., preferably 100 ° C. to 150 ° C., and the drying time is usually 5 seconds to 1 minute, preferably 10 seconds to 30 seconds. In this way, the oil resistant paper of the present invention can be obtained. The oil-resistant paper of the present invention obtained after drying may be formed as a coating layer in which the solid content of the oil-resistant agent is laminated directly or indirectly on the surface of the paper substrate, or in the paper substrate. It may be included in an impregnated state.

In FIG. 1, the specific example using the oil-resistant paper of this invention is shown. In FIG. 1, solid printing is performed with nitrified cotton or acrylic ink on the oil-resistant coating layer of the oil-resistant paper of the present invention in which the oil-resistant coating layer (solid content of the oil-resistant agent) is laminated on the base paper (paper substrate). A white solid layer is formed, a picture layer is further formed on the white solid layer, and a top coat layer is formed using a urethane-based resin or the like. Further, as shown in FIG. 2, a white solid layer is formed on a base paper (paper base material), a pattern layer is formed thereon, and the oil-proofing agent of the present invention is applied on the pattern layer, followed by drying. Then, an oil-resistant coat layer may be formed, and a top coat layer may be formed thereon.
After applying the oil-proofing agent of the present invention and drying it, a winding operation or a printing operation can be performed immediately. Furthermore, the wound raw material may be cured for 1 to 7 days, preferably 2 to 4 days in an atmosphere of 40 to 100 ° C., preferably 50 to 80 ° C., and has a high surface hardness and wear resistance. Oil-resistant paper having heat resistance, stain resistance and heat resistance can be obtained.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the measurement evaluation in an Example and a comparative example was performed by the method shown below.

<Hydrolysis rate>
The hydrolysis rate of the silicate having a silanol group obtained by hydrolyzing the silicate was measured by an infrared absorption spectrum.
Each absorption wavelength (peak intensity) of the infrared absorption spectrum is as follows.
3400 cm ^-1: vibration absorption 2840cm OH groups due to Si-OH ^-1: vibration absorption of the CH3 groups resulting from the ^{Si-OCH3 1100cm -1: Si-} O-Si vibrations absorption due to Si-O-Si

<Methoxy group content>
The content of methoxy group (Si—OCH 3) in methyl silicate containing Si—OH group is determined from two infrared spectrum diagrams of methyl silicate containing no Si—OH group and methyl silicate containing Si—OH group. 100% methoxy proportion of methyl silicate calculating the ratio of the peak attributed to methoxy groups (2840cm ^-1), does not contain Si-OH groups to the strongest peak due to -Si (1100cm ^-1), the It was calculated from the ratio. FIG. 3 shows an infrared absorption spectrum of methyl silicate containing no Si—OH group [methyl silicate which is a tetramer of tetramethyl silicate (methyl silicate 51, manufactured by Colcoat Co., Ltd.)]. The infrared absorption spectrum figure of the polysiloxane containing the Si-OH group obtained in Example 1-1 is shown.

<Silanol group ratio>
The ratio (mol%) of silanol groups to the total amount of silanol groups and alkoxy groups of the resulting polysiloxane is the remainder from the above methoxy group content [100 mol%-methoxy group content (mol%)]. Was the silanol group ratio (mol%).

<Average polymerization degree n>
The average degree of polymerization n of the obtained polysiloxane is obtained by measuring the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography). GPC uses a polystyrene gel-filled column “Shodex KF-2002 and Shodex KF-2004 connected in series as a packed column” manufactured by Showa Denko KK as a separation column, and tetrahydrofuran as an effluent. , Measured at a flow rate of 2.0 ml / min and an outflow temperature of 30 ° C.

<Content of polysiloxane in oil resistant agent>
The content of polysiloxane in the obtained oil resistant agent was determined by the evaporation to dryness method.

<Blocking resistance>
The blocking resistance of the obtained oil resistant paper was evaluated by the following method.
○: After aging at 40 ° C. for 3 days, the printed papers are not adhered to each other.
Δ: After aging at 40 ° C. for 3 days, the printed paper has a tacky feeling (smoothness).
X: After aging at 40 ° C. for 3 days, the printed papers adhere to each other and break when peeled off.

<Oil resistance>
The oil resistance of the obtained oil resistant paper was evaluated by the following method.
○: Liquid paraffin was dripped and no osmotic diffusion was observed even after 1 day.
Δ: Liquid paraffin was dripped, and a part of the permeation diffused after 1 day was observed.
X: Liquid paraffin was dripped, and the entire surface diffused and diffused after one day.

<Stability over time>
The stability over time of the obtained oil resistant agent was evaluated by the following method.
○: Standing in an atmosphere of 50 ° C., fluidity is maintained even after 1 month or more.
X: It leaves still in 50 degreeC atmosphere and gelatinizes within one month.

<Kit value>
The kit value of the obtained oil resistant paper was measured by the following method.
JAPAN TAPPI Paper Pulp Test Method NO. 41: 2000, “Paper and paperboard—Oil repellency test method—Kit value”. In carrying out 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, five or more oil-resistant papers cut to a size of about 50 mm × 50 mm were prepared as test pieces and subjected to an oil repellency test. In addition, it shows that oil resistance is so strong that the value of a kit value is large, it can apply to various oils, and can also endure long-time contact with oil.

Example 1-1 (Production of oil-proofing agent)
In a reaction apparatus equipped with a stirrer, a thermometer, and a nitrogen blowing port, methyl silicate (methyl silicate 51, manufactured by Colcoat Co., Ltd.), which is a tetramer of tetramethoxysilane [in the general formula (1), R ₁ , R ₂ , 1 kg of a compound in which all of R ₃ and R ₄ are methyl groups and n is 4], and 1 kg of isopropyl alcohol are mixed at room temperature, and then 100 g of 0.1 molar hydrochloric acid and 90 g of water [into 1 mol of methoxy group] This corresponds to 0.5 mol of water. ] And diluted with 100 g of methanol was added little by little with stirring to conduct hydrolysis. The temperature gradually increased and reached 40 ° C. after 30 minutes to obtain a silicate in which 37 mol% of all methoxy groups were silanol groups (37% hydrolysis rate). When stirring was continued as it was, the temperature gradually decreased, and stirring was further continued for 5 hours to obtain a reaction mixture containing a silicate hydrolysis condensate (1-1). It was confirmed by analysis that a polysiloxane having n of 10 represented by the general formula (1) was obtained in the reaction mixture. The analysis confirmed that the ratio of silanol groups to the total amount of silanol groups and methoxy groups in the polysiloxane was 37 mol%. The reaction mixture contained 45% by mass of polysiloxane [silicate hydrolysis condensate (1-1)]. The results are shown in Table 1. In addition, the infrared absorption spectrum figure of the methyl silicate 51 used as a manufacturing raw material is shown in FIG. 3, and the infrared absorption spectrum figure of the obtained polysiloxane is shown in FIG.

Example 1-2 (Production of oil-proofing agent)
A solution prepared by dissolving 1 kg of glycidoxypropyltriethoxysilane (silane coupling agent) in 1 kg of isopropyl alcohol was gradually added dropwise to the reaction mixture obtained in Example 1-1, and glycidoxypropyltriethoxysilane was mixed. A reaction mixture containing polysiloxane (1-2) modified in step 1 was obtained. When the modified polysiloxane (1-2) in the reaction mixture was analyzed, 1.7 × 10 ⁻² mol% of the methoxy group was modified with glycidoxypropyltriethoxysilane. The reaction mixture contained 43% by mass of polysiloxane (1-2) modified with glycidoxypropyltriethoxysilane.

Example 2-1 (Production of Oil Resistant Paper)
The reaction mixture containing the polysiloxane [silicate hydrolysis condensate (1-1)] obtained in Example 1-1 was used as an oil-proofing agent, and coated with a gravure coating machine. Coating uses thin base paper for building materials (weighing 30 g / m ² ) and prints using a gravure plate so that polysiloxane [hydrolyzed condensate of silicate (1-1)] has a dry weight of 5 g / m ^2. The coating was carried out at a speed of 100 m / min, and after coating, it was dried for 15 seconds in a 130 ° C. drying oven. Immediately after drying, it was wound up and allowed to stand in a aging room at 40 ° C. for 1 day for aging. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

Example 2-2 (production of oil-resistant paper)
The reaction mixture containing the modified polysilokine (1-2) obtained in Example 1-2 was used as an oil resistance agent, and coated with a gravure coating machine. Coating is performed using thin base paper for building materials (weighing 30 g / m ² ), using a gravure plate so that the modified polysiloxane (1-2) has a dry weight of 5 g / m ^2, and is applied at a printing speed of 100 m / min. And after coating, it was dried in a drying furnace at 130 ° C. for 15 seconds. Immediately after drying, it was wound up and allowed to stand in a aging room at 40 ° C. for 1 day for aging. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

Example 3 (Production of oil-proofing agent)
Methyl silicate (methyl silicate 53A, manufactured by Colcoat Co., Ltd.) [Tetramethoxysilane heptamer] [In the general formula (1), R ₁ , R ₂ , 1 kg of a compound in which all of R ₃ and R ₄ are methyl groups and n is 7] and 1 kg of methyl alcohol are mixed at room temperature, and then 60 g of acetic acid (20% by mass aqueous solution) is added to 210 g of water (1 mol of methoxy group). It corresponds to 0.7 molar amount of water. ] And a solution diluted with 100 g of methanol were gradually added with stirring to perform hydrolysis. The temperature gradually increased and reached 50 ° C. after 20 minutes to obtain a silicate in which 70 mol% of all methoxy groups were silanol groups (70% hydrolysis rate). When stirring was continued as it was, the temperature gradually decreased, and stirring was further continued for 5 hours to obtain a reaction mixture containing the silicate hydrolysis condensate (2). It was confirmed by analysis that polysiloxane having n of 14 represented by the general formula (1) was obtained in the reaction mixture. The ratio of silanol groups to the total amount of silanol groups and methoxy groups in the polysiloxane was 70 mol% after complete hydrolysis. The reaction mixture contained 44% by mass of polysiloxane [silicate hydrolysis-condensation product (2)]. The results are shown in Table 1.

Example 4 (Production of oil-resistant paper)
Dry weight of polysiloxane [silicate hydrolysis condensate (2)] using the reaction mixture containing polysiloxane [silicate hydrolysis condensate (2)] obtained in Example 3 as an oil resistance agent Using a gravure plate so as to be 7 g / m ² , coating was performed at a printing speed of 100 m / min. After coating, the coating was dried in a drying furnace at 140 ° C. for 15 seconds. Immediately after drying, it was wound up and allowed to stand in an aging room at 40 ° C. for 1 day for aging to obtain an oil-resistant paper. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

Example 5 (Production of oil-proofing agent)
Ethyl silicate (ethyl silicate 40, manufactured by Colcoat Co., Ltd.), which is a pentamer of tetraethoxysilane, in a reactor equipped with a stirrer, a thermometer, and a nitrogen blowing port [in the general formula (1), R ₁ , R ₂ , 1 kg of a compound in which all of R ₃ and R ₄ are ethyl groups and n is 5] and 1 kg of ethyl alcohol are mixed at room temperature, and then 20 g of 0.1 molar hydrochloric acid is added to 80 g of water [based on 1 mol of ethoxy groups] Equivalent to 0.41 molar amount of water. ] And those diluted with 100 g of ethyl alcohol were added little by little with stirring to conduct hydrolysis. The temperature gradually increased and reached 45 ° C. after 30 minutes to obtain a silicate in which 41 mol% of all ethoxy groups were silanol groups (41% hydrolysis rate). When stirring was continued as it was, the temperature gradually decreased, and stirring was further continued for 5 hours to obtain a reaction mixture containing the silicate hydrolysis condensate (3). It was confirmed by analysis that a polysiloxane having n of 10 represented by the general formula (1) was obtained in the reaction mixture. The ratio of silanol groups to the total amount of silanol groups and ethoxy groups in the polysiloxane was 41 mol% after complete hydrolysis. The reaction mixture contained 45 mass% of polysiloxane [silicate hydrolysis condensate (3)]. The results are shown in Table 1.

Example 6 (Production of oil-resistant paper)
Dry weight of polysiloxane [silicate hydrolysis condensate (3)] using the reaction mixture containing polysiloxane [silicate hydrolysis condensate (3)] obtained in Example 5 as an oil resistance agent Using a Meyer bar coater so as to be 7 g / m ² , the building material thin paper used in Example 2 was coated at a printing speed of 100 m / min, and after coating, it was coated in a 140 ° C. drying oven for 15 seconds. Dried. Immediately after drying, it was wound up and allowed to stand in an aging room at 40 ° C. for 1 day for aging to obtain an oil-resistant paper. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

Comparative Example 1 (Manufacture of oilproofing agent)
1 kg of tetramethoxysilane silicate (M silicate 51, manufactured by Colcoat Co., Ltd.) and 1 kg of isopropyl alcohol are mixed, and 100 g of titanium tetrapropoxide and 1 kg of isopropyl alcohol are gradually added. By stirring for a period of time, titanium tetrapropoxide was added to a part of the silicate for modification. It was confirmed that the addition amount of titanium tetrapropoxide was 1.7 × 10 ⁻² mol% with respect to all methoxy groups. The resulting reaction mixture contained 51% by mass of silicate added with titanium tetrapropoxide. The results are shown in Table 1.

Comparative Example 2 (Production of oil-resistant paper)
Using the reaction mixture obtained in Comparative Example 1 as an oil-resistant agent, printing speed of 50 m / min was applied to the thin base paper for building materials used in Example 2 in the gravure coating machine so as to have a dry weight of 10 g / m ^2. After coating, the film was dried in a drying furnace at 120 ° C. for about 30 seconds. Immediately after drying, it was wound up and left in an aging room at 40 ° C. for 3 days for aging to obtain an oil-resistant paper. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

Comparative Example 3 (Production of oil resistant agent)
A reactor equipped with a stirrer, a thermometer, and a nitrogen blowing port was mixed with 1 kg of ethyl silicate (ethyl silicate 40, manufactured by Colcoat Co.) 1 kg and 1 kg of isopropyl alcohol at room temperature. .40 g of 1 mol hydrochloric acid and 200 g of water [corresponds to 1.0 mol of water per mol of ethoxy groups. The solution diluted with 200 g of methanol was gradually added with stirring to perform hydrolysis. The temperature gradually increased and reached 40 ° C. after 30 minutes to obtain a silicate in which all of the ethoxy groups (100 mol%) were silanol groups (100% hydrolysis rate). When stirring was continued as it was, the temperature gradually decreased, and stirring was further continued for 5 hours to obtain 2.4 kg of a reaction mixture containing a silicate hydrolysis condensate (5). In the reaction mixture, in the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are all hydrogen atoms, and n is 15, polysiloxane [silicate hydrolysis condensate (5) ] Was obtained. The ratio of silanol groups to the total amount of silanol groups and alkoxy groups in the polysiloxane is 100 mol%. The results are shown in Table 1.

Comparative Example 4 (Production of oil-resistant paper)
The reaction mixture containing the polysiloxane [silicate hydrolysis condensate (5)] obtained in Comparative Example 3 was used as an oil-proofing agent in Example 2 using a gravure coating machine so that the dry weight was 7 g / m ^2. The thin base paper for building materials used was coated at a printing speed of 100 m / min, and dried for about 15 seconds in a drying furnace at 150 ° C. after coating. Immediately after drying, the paper was wound up and left in an aging room at 40 ° C. for 3 days for aging to obtain an oil-resistant paper. Each evaluation test was performed about the obtained oil-resistant paper. The results are shown in Table 2.

  As shown in Examples 2, 4 and 6 of Table 2, the oil resistant paper obtained using the oil resistant agent of the present invention is excellent in blocking resistance, oil resistance, stability over time and kit value, and has an excellent oil resistant agent. You can see that On the other hand, in the oil-resistant paper of Comparative Example 2, since silanol groups are not included in the polysiloxane, the blocking resistance and oil resistance are not good. In the oil-resistant paper of Comparative Example 4, alkoxy groups are contained in the polysiloxane. Since it is not contained, it turns out that blocking resistance and temporal stability are not good.

  The oil-resistant agent of the present invention has little influence on the environment and can provide an oil-resistant paper excellent in blocking resistance, oil resistance and heat resistance, and thus is widely used for food applications, building materials applications, various industrial materials, etc. be able to.

Claims (7)

An oilproofing agent comprising polysiloxane represented by the following general formula (1).
[In the general formula (1), R ₁ , R ₂ , R ₃ and R ₄ are any one selected from a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and R ₁ , R ₂ , R ₃ and A part of R ₄ is a hydrogen atom. n is an average degree of polymerization and is 4-20. ]   The oilproofing agent according to claim 1, wherein in the general formula (1), the alkyl group having 1 to 4 carbon atoms is at least one selected from a methyl group or an ethyl group.   The oilproofing agent of Claim 1 or 2 whose ratio of the silanol group with respect to the total amount of the silanol group and alkoxy group in the polysiloxane represented by the said General formula (1) is 30-50 mol%.   The polysiloxane represented by the general formula (1) is a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms, or a silicate having an average polymerization degree of 4 to 10 and having an alkoxy group having 1 to 4 carbon atoms. Any one of claims 1 to 3, which is obtained by hydrolysis in alcohol using 0.2 to 0.5 mol of water per mol of alkoxy group, and then polycondensation. Oilproofing agent as described in 4.   A part of the polysiloxane represented by the general formula (1) is modified with 0.01 to 0.1 mol of a silane coupling agent with respect to 1 mol of an alkoxy group in the polysiloxane. The oil-proof agent in any one of -4.   The oil-proof agent in any one of Claims 1-5 in which 15-80 mass% of said polysiloxane is contained.   An oil resistant paper obtained by applying the oil resistant agent according to any one of claims 1 to 6.