JP2020023759A - Flame-retardant paper - Google Patents

Abstract

To provide flame-retardant paper having high flame resistance especially suitable for a member of an electromagnetic wave absorber, difficulty to form paper rupture in a production process, and good productivity.SOLUTION: The flame-retardant paper of the present invention is flame-retardant paper containing a pulp, aluminium hydroxide, a guanidine-based flame retardant and a urethane resin. The flame-retardant paper is characterized by that the content of the pulp is 10-35 mass%, the content of the aluminium hydroxide is 40-70 mass%, the content of the guanidine-based flame retardant is 0.1-15 mass%, and the content of the urethane resin is 0.1-2 mass%.SELECTED DRAWING: None

Description

  The present invention relates to flame retardant paper.

  2. Description of the Related Art Conventionally, development of paper having flame retardancy has been demanded in many fields. For example, paper is widely used in electric and electronic materials, industrial materials, and the like, and in some of these fields, there is an increasing demand for the development of flame-retardant paper.

  Known methods for imparting flame retardancy to paper include application or impregnation of a flame retardant, internal addition of a flame retardant organic substance or inorganic powder, blending of inorganic fibers, or a combination thereof. More specifically, for example, flame retardant paper containing flame retardant fibers and aluminum hydroxide has been proposed (see Patent Document 1).

  Further, flame-retardant paper and the like for a radio wave absorber member used in an anechoic chamber have been used for more than 10 years, and it is desired that the flame retardancy during that time is suppressed.

  In order to solve the above-mentioned demands, a flame-retardant paper for a radio wave absorber member containing pulp and a flame retardant composed of aluminum hydroxide and polyborate has been proposed (see Patent Document 2).

International Publication No. 2014/088019 International Publication No. WO 2017/002863

  According to the knowledge of the present inventors, the flame retardant paper and the flame retardant paper for a radio wave absorber member proposed in Patent Documents 1 and 2 described above have relatively low toughness of the flame retardant paper, and are difficult to impregnate or apply. There is a tendency for the flame-retardant paper to break during drying in the chemical application step and during secondary processing such as slitting and printing, and there is a processing problem that the productivity of the flame-retardant paper is reduced.

  Accordingly, an object of the present invention is to provide, in addition to having high flame retardancy suitable for a member of a radio wave absorber, in addition to secondary drying such as drying or slitting or printing in a drug application step such as impregnation or application. An object of the present invention is to provide a flame-retardant paper which is less likely to break during processing and has good productivity.

  In order to achieve the above-mentioned object, the flame-retardant paper of the present invention is (1) a flame-retardant paper containing pulp, aluminum hydroxide, a guanidine-based flame retardant and a urethane resin. Is 10 to 35% by mass, the content of the aluminum hydroxide is 40 to 70% by mass, the content of the guanidine-based flame retardant is 0.1 to 15% by mass, and the urethane resin is Is 0.1 to 2% by mass.

  (2) In the flame-retardant paper of (1), the mass ratio of the guanidine-based flame retardant contained in the flame-retardant paper to the urethane resin (guanidine-based flame retardant / urethane resin) is 50/50 or more and 95 /. 5 or less.

  According to the present invention, in addition to having high flame retardancy, it is difficult for the flame-retardant paper to break during drying and in secondary processing such as slitting or printing in a drug application step such as impregnation or coating. Thus, a flame-retardant paper having good productivity can be obtained.

  Hereinafter, an example of an embodiment of the present invention will be described.

  The flame-retardant paper of the present invention is a flame-retardant paper containing pulp, aluminum hydroxide, a guanidine-based flame retardant and a urethane resin, wherein the content of the pulp is 10 to 35% by mass based on the flame-retardant paper. The content of the aluminum hydroxide is 40 to 70% by mass, the content of the guanidine-based flame retardant is 0.1 to 15% by mass, and the content of the urethane resin is 0.1 to 2% by mass. %.

  The flame-retardant paper of the present invention adopting the above configuration has excellent flame retardancy, while suppressing the occurrence of breakage of the flame-retardant paper at the time of drying in a drug application step such as impregnation or application. By doing so, it also has excellent productivity. The reason is presumed as follows. First, as described in detail below, the flame-retardant paper needs to contain a specific amount or more of pulp in order to form the flame-retardant paper as paper. Since pulp is a relatively flammable material, the content of flame retardants such as aluminum hydroxide and guanidine-based flame retardants in flame-retardant paper is required to ensure sufficient flame retardancy of flame-retardant paper. Must be equal to or more than a specific amount. On the other hand, when the content of the flame retardant in the flame-retardant paper increases, the toughness of the flame-retardant paper decreases, and the frequency of rupture of the flame-retardant paper increases during drying in a chemical application process such as impregnation or application. I do. However, since the flame-retardant paper contains a urethane resin, and further contains pulp, aluminum hydroxide, a guanidine-based flame retardant and a urethane resin at specific contents, the toughness of the flame-retardant paper is reduced. It is higher and has high levels of moldability and flame retardancy as paper of flame-retardant paper, and furthermore, breakage of flame-retardant paper at the time of drying in a chemical application process such as impregnation or coating etc. It is presumed that it is possible to obtain a flame-retardant paper which suppresses the occurrence of odor and is excellent in productivity. It should be noted that the formability of the flame-retardant paper as a paper and the flame retardancy inherently have a trade-off relationship due to the above circumstances.

  As the pulp used in the flame-retardant paper of the present invention, softwood pulp, hardwood pulp, thermomechanical pulp, groundwood pulp, pulp composed of plant fibers such as linter pulp and hemp pulp, pulp composed of regenerated fibers such as rayon, and vinylon And synthetic fiber pulp made of polyester or the like. One or more types of pulp can be appropriately selected from these and used.

  The flame retardant paper of the present invention contains 10 to 35% by mass of pulp based on the entire flame retardant paper. When the content of the pulp is less than 10% by mass, the entanglement force of the pulp is weakened in the paper making process, and it is difficult to form a sheet state. On the other hand, if the pulp content exceeds 35% by mass, there is a tendency that sufficient flame retardancy cannot be obtained as flame retardant paper.

  Thus, by setting the content of the pulp in the range of 10 to 35% by mass, a sheet having excellent flame retardancy of the flame retardant paper can be obtained.

  Next, the flame retardant paper of the present invention contains 40 to 70% by mass of aluminum hydroxide. Since the aluminum hydroxide is preferably supported in a state of being sufficiently dispersed throughout the flame retardant paper, the aluminum hydroxide is preferably a powder.

  Here, aluminum hydroxide is dehydrated and decomposed at a high temperature, and an endothermic effect at that time provides a flame retardant effect. This flame-retardant effect does not decrease over time even after long-term storage, and enables the flame-retardant effect imparted to the flame-retardant paper to be maintained for a long time.

  In addition, aluminum hydroxide is adsorbed to pulp by appropriately adding a papermaking agent such as a retention enhancer or a paper strength enhancer composed of a cationic polymer compound or an anionic polymer compound during papermaking of flame-retardant paper. It contributes by improving the flame retardancy of paper.

  Further, since aluminum hydroxide is a white powder, the color of flame-retardant paper containing aluminum hydroxide at a specific content or more is white. Therefore, when the flame retardant paper of the present invention is used for a radio wave absorber for an anechoic chamber, for example, the indoor lighting effect can be enhanced. Further, the aluminum hydroxide does not discolor, and the flame retardant paper can be maintained white.

  When the content of aluminum hydroxide is less than 40% by mass, the flame retardant paper may not be able to obtain sufficient flame retardancy. In the case where the content of aluminum hydroxide is less than 40% by mass, the ratio between the content of aluminum hydroxide and the content of pulp in the flame retardant paper (content of aluminum hydroxide / content of pulp) When the flame-retardant paper is used as a flame-retardant paper for a radio wave absorber member, the pulp content in the flame-retardant paper increases with respect to the aluminum hydroxide content in the flame-retardant paper. Discoloration due to aging of the fuel paper becomes noticeable.

  On the other hand, when the content of aluminum hydroxide is more than 70% by mass, the flame-retardant paper can obtain high flame retardancy. During the secondary processing, the flame-retardant paper may be broken, and the handleability and processability may deteriorate.

  Thus, by setting the content of aluminum hydroxide in the range of 40 to 70% by mass, it is possible to obtain a flame-retardant paper having excellent flame retardancy and white color retention of the flame-retardant paper. Aluminum hydroxide can be purchased from Fujifilm Wako Pure Chemical Industries, Ltd. and Sigma-Aldrich Japan Co., Ltd.

  Examples of the guanidine-based flame retardant used in the flame-retardant paper of the present invention include guanidine phosphate, guanylurea phosphate, guanidine sulfamate, guanidine carbonate, and the like. Can be selected and used. In general, if the required amount of the flame retardant is large, the toughness of the flame retardant paper decreases, so that the flame retardant paper breaks during drying in the chemical application process such as impregnation or application and during secondary processing such as slitting and printing. Tends to occur. The tendency of the toughness of flame-retardant paper to decrease is greater for guanidine-based flame retardants than for aluminum hydroxide. Among these guanidine-based flame retardants, it is preferable to use guanidine phosphate which has a high flame retardant effect particularly on a cellulose material and can ensure the flame retardancy of the flame retardant paper at least in a required amount of the contained flame retardant.

  The flame retardant paper of the present invention contains 0.1 to 15% by mass of a guanidine-based flame retardant based on the entire flame retardant paper.

  When the content of the guanidine-based flame retardant with respect to the entire flame retardant paper is 0.1% by mass or less, the flame retardancy of a member obtained by laminating the flame retardant paper and the styrene foam tends to be insufficient. From the above viewpoint, the content of the guanidine-based flame retardant is more preferably 2% by mass or more.

  On the other hand, when the content of the guanidine-based flame retardant with respect to the whole flame retardant paper is 15% by mass or more, the flame retardant paper is dried at the time of applying the agent by impregnation or coating and at the time of secondary processing such as slitting or printing. Breakage may occur, and handleability and processability may deteriorate. Further, when used as a flame retardant paper for a radio wave absorber member, discoloration due to aging becomes noticeable.

  The flame retardant paper of the present invention contains a urethane resin in an amount of 0.1 to 2% by mass based on the entire flame retardant paper. The urethane resin can improve the toughness of the flame-retardant paper by being contained in the flame-retardant paper, so that it is used during drying in the chemical application step such as impregnation or application and during secondary processing such as slitting and printing. It is possible to suppress the breakage of the flame retardant paper.

  When the content of the urethane resin with respect to the entire flame-retardant paper is 0.1% by mass or less, the flame-retardant paper breaks during drying in the chemical application step such as impregnation or application and during secondary processing such as slitting and printing. Occurs, and the handleability and process passability may deteriorate.

  On the other hand, when the content of the urethane resin with respect to the entire flame-retardant paper is 2% by mass or more, the urethane resin adheres to the coating device or the drying roll in the chemical application step, and the equipment needs to be periodically cleaned. , The productivity may decrease.

  The flame retardant paper of the present invention preferably has a mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) of 50/50 or more and 95/5 or less.

  Here, the mass ratio of the guanidine-based flame retardant to the urethane resin (guanidine-based flame retardant / urethane resin) will be described. Trade-offs are made between the flame retardancy of members made by laminating flame-retardant paper and Styrofoam, and the suppression of breakage of flame-retardant paper during drying in the chemical application process such as impregnation and application, and during secondary processing such as slitting and printing. In a relationship. That is, when the mass ratio of the guanidine-based flame retardant to the urethane resin (the guanidine-based flame retardant / urethane resin) contained in the flame-retardant paper is increased, the flame retardancy of the member in which the flame-retardant paper and the styrene foam are bonded is more excellent. It will be. On the other hand, if the mass ratio (guanidine-based flame retardant / urethane resin) of the guanidine-based flame retardant to the urethane resin contained in the flame-retardant paper is reduced, it is possible to reduce Breakage of the flame-retardant paper during secondary processing such as slitting and printing is further suppressed.

  In view of the above, by setting the mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) in the range of 50/50 or more and 95/5 or less, flame-retardant paper and styrofoam were bonded. A flame-retardant paper that achieves a higher level of flame retardancy of the member and a higher level of suppression of breakage of the flame-retardant paper during drying in the chemical application step in impregnation and application and during secondary processing such as slitting and printing. . The mass ratio (guanidine-based flame retardant / urethane resin) of the guanidine-based flame retardant to the urethane resin contained in the flame-retardant paper is within the range of 50/50 or more and 95/5 or less, depending on the purpose. It is preferable to select an appropriate one.

  The flame retardant paper of the present invention may contain inorganic fibers such as glass fibers, rock wool, and basalt fibers. Since these are inorganic fibers, they can improve the flame retardancy of flame-retardant paper, and because they are highly rigid fibers, they can express a high degree of rigidity with flame-retardant paper, improving the handleability of flame-retardant paper. Can be improved. The content of the inorganic fiber is preferably in the range of 1 to 30% by mass when the entire flame retardant paper of the present invention is 100% by mass. More preferably, the content is 20% by mass or less. Within this range, flame-retardant paper having high rigidity can be stably manufactured.

  The flame retardant paper of the present invention can contain a conductive substance. The conductive substance in the present invention, when the flame-retardant paper is used as a flame-retardant paper for a radio wave absorber member, converts the radio wave energy into a minute current, and further converts it into heat energy, thereby attenuating the radio wave, That is, it is a material that absorbs radio waves. Examples of the conductive substance include conductive particles and conductive fibers. Here, examples of the conductive particles include metal particles, carbon black particles, carbon nanotube particles, carbon microcoil particles, and graphite particles. Examples of the conductive fiber include carbon fiber and metal fiber, and examples of the metal fiber include stainless steel fiber, copper fiber, silver fiber, gold fiber, nickel fiber, aluminum fiber, and iron fiber. In addition, non-conductive particles and fibers obtained by imparting conductivity by plating, vapor deposition, and thermal spraying of a metal can also be mentioned as the conductive substance.

  Among these conductive substances, conductive fibers are preferably used, and among conductive fibers, conductive short fibers are more preferably used. Since the conductive short fibers have a large aspect ratio, the fibers are likely to come into contact with each other, and the radio wave absorption performance can be effectively obtained even in a small amount as compared with powder. Among the conductive short fibers, carbon fibers are particularly preferably used because the fibers are rigid and easily oriented in the base material, and there is almost no change in performance during long-term use. The length of the conductive short fiber is preferably 0.1 mm or more, more preferably 1.0 mm or more, from the viewpoint of the ease of contact between the fibers and the dispersibility of the slurry in the paper making process described below. On the other hand, it is preferably 15.0 mm or less, more preferably 10.0 mm or less.

  In the flame-retardant paper of the present invention, the content of the conductive substance is preferably 0.05 to 5 parts by mass based on 100 parts by mass of the raw material of the flame-retardant paper excluding the conductive substance. Further, the content is preferably at least 0.1 part by mass. On the other hand, the content is preferably at most 4 parts by mass, more preferably at most 3 parts by mass.

The basis weight of the flame-retardant paper of the present invention is preferably in the range of 50 to 200 g / m ² . When the basis weight is within this range, the toughness of the flame-retardant paper is improved, and the flame-retardant paper is difficult to be dried at the time of applying a drug in impregnation or application of the flame-retardant paper and at the time of secondary processing such as slitting and printing. The breaking of the fuel paper can be suppressed. The basis weight is preferably 80 g / m ² or more. On the other hand, it is preferably 150 g / m ² or less.

  Next, a method for producing the flame-retardant paper of the present invention will be described.

  The method for producing flame-retardant paper according to the present invention is such that the content of pulp is 10 to 35% by mass with respect to the flame-retardant paper, and the content of aluminum hydroxide is 40 to 70% by mass with respect to the flame-retardant paper. A step of obtaining a flame-retardant paper base material by wet papermaking of pulp and aluminum hydroxide, wherein the content of the guanidine-based flame retardant with respect to the flame-retardant paper is 0.1 to 15% by mass, and And a step of applying a guanidine-based flame retardant and a urethane resin to the flame-retardant paper base material in this order so that the content of the urethane resin is 0.1 to 2% by mass. As a method for producing the flame-retardant paper of the present invention, as one example, a method of making a known paper material can be used. A wet papermaking method and the like, in which a slurry in which fibers (pulp), aluminum hydroxide, and the like, which are constituent materials of the flame-retardant paper of the present invention, and water and the like are mixed, are made with a paper machine.

  As the paper machine, any paper machine such as a circular net, a short net, a long net, a perch former, a rotoformer, and a hydroformer can be used. As the dryer, any dryer such as a Yankee type, a multi-cylinder type, and a through type can be used.

  Further, the method of incorporating the guanidine-based flame retardant and the urethane resin into the flame retardant paper is not particularly limited. For example, internal addition, impregnation application, coating application and the like can be exemplified. Coating devices such as a size press coater, a roll coater, a blade coater, a bar coater, and an air knife coater can be used for impregnation coating and coating coating, and these devices can be used on-machine or off-machine.

  As a method for incorporating the urethane resin into the flame retardant paper, impregnation coating is more preferable. By incorporating the urethane resin into the flame-retardant paper by impregnation coating, the urethane resin forms a film on the surface of the flame-retardant paper and more effectively improves the toughness of the flame-retardant paper. Breakage of the flame-retardant paper can be further suppressed at the time of drying in a drug application step such as coating and at the time of secondary processing such as slitting and printing.

  Further, as a method of adding conductive fibers to the flame-retardant paper, a method of mixing the conductive fibers in the above-mentioned slurry and shaping into the flame-retardant paper or a method of mixing the conductive fibers with the binder resin material is used. , A size press coater, a roll coater, a blade coater, a bar coater, an air knife coater and the like, and a method of applying the composition to flame retardant paper.

  Next, the flame retardant paper of the present invention will be described in more detail with reference to examples. The performance values shown in the examples were measured by the following methods.

[Measuring method]
(1) Confirmation of the components contained in the flame retardant paper The components contained in the flame retardant paper are confirmed as follows. That is, by using an ultra-high resolution field emission scanning electron microscope (SEM, SU-8010 manufactured by Hitachi High-Technologies Corporation), from the four corners of a flame-retardant paper test piece of 10 cm × 10 cm to the center of the test piece, An energy dispersive X-ray analysis is performed by photographing a total of five regions including four regions around a point shifted by 2.5 cm in the horizontal direction and one region around one point at the center of the test piece. The presence of a specific element was confirmed by an apparatus (EDX), and the test piece was measured for flame retardancy using an infrared spectrophotometer (FT-IR, IR PRESTIGE-21 manufactured by Shimadzu Corporation). Check the components contained in the paper.

(2) Basis Weight of Flame Retardant Paper Five pieces of flame retardant paper are cut into a square of 300 mm on a side, the mass is measured, converted to the mass per 1 m ² , and the average value is taken to calculate the basis weight. .

(3) Flame Retardancy of Flame Retardant Paper Evaluate based on the 20 mm vertical burn test (UL94 V-0) in UL94 safety standard (“Test for plastic material flammability of equipment and appliance parts”). Here, UL refers to U.S. Underwriters Laboratories Inc. Is a safety standard for electronic devices that has been established and permitted, and UL94 is also a flame-retardant standard.
◎: For all five levels, measure the burning time between 100 mm (from the 25 mm line to the 125 mm line), calculate the burning speed, and there must be no sample burning at a burning speed exceeding 40 mm / min. Alternatively, the sample must be extinguished before the combustion or fire reaches the 125 mm line. Furthermore, the average value of the burning rates of the burned samples must be less than 35 mm / min.
○: For all five levels, measure the burning time between 100 mm (from the 25 mm line to the 125 mm line), calculate the burning speed, and there must be no sample burning at a burning speed exceeding 40 mm / min. Alternatively, the sample must extinguish before the combustion or fire reaches the 125 mm line. Further, the average value of the burning rate of the burned sample must be 35 mm / min or more and 40 mm / min or less.
×: At least one of the five does not satisfy the above criteria of ◎ and / or ○.

(4) Flame retardancy of a member in which flame-retardant paper and styrofoam are bonded together The flame-retardant paper and styrofoam having a thickness of 10 mm are bonded with a double-sided tape (recycled paper double-sided tape NWBB-15, manufactured by Nichiban Co., Ltd.) Produces a member in which flame retardant paper and styrofoam are joined.

The above members are evaluated for the burning rate in accordance with the foam material horizontal flammability test (UL94 HBF) in the UL94 safety standard ("Plastic material flammability test of equipment and appliance parts").
◎: For all five levels, measure the burning time between 100 mm (from the 25 mm line to the 125 mm line), calculate the burning speed, and there must be no sample burning at a burning speed exceeding 40 mm / min. Alternatively, the sample must extinguish before the combustion or fire reaches the 125 mm line. Furthermore, the average value of the burning rates of the burned samples must be less than 35 mm / min.
○: For all five levels, measure the burning time between 100 mm (from the 25 mm line to the 125 mm line), calculate the burning speed, and there must be no sample burning at a burning speed exceeding 40 mm / min. Alternatively, the sample must extinguish before the combustion or fire reaches the 125 mm line. Furthermore, the average value of the burning rate of the burned sample must be 35 mm / min or more and 40 mm / min or less.
×: At least one of the five does not satisfy the above criteria of ◎ and / or ○.

(5) Breakability The presence or absence of breakage of the flame retardant paper was confirmed by the following method. After drying the flame-retardant paper cut into a square of 100 mm at 80 ° C. for 120 seconds, it is cooled at room temperature for 10 seconds, and the number of times a rip is formed by repeating mountain folds and valley folds is recorded (the upper limit is 20 times). ). Here, it can be said that as the number of times of bending is increased before a tear is formed, the flame retardant paper is less likely to break.

(6) Papermaking productivity In the case of wet papermaking by the continuous papermaking method, stable continuous productivity was confirmed by the following evaluation.
A: Papermaking could be stably produced.
B: The paper was broken during the paper making, or the urethane resin was attached to the coating equipment or the drying roll, and stable paper making could not be performed.

[Example 1]
As a pulp, 15% by mass of softwood pulp having a fiber length of 5 mm, 66% by mass of aluminum hydroxide (Wako Pure Chemical Industries, Ltd.) and 15% by mass of glass fiber are mixed, and wet papermaking is performed by a continuous papermaking method. A fuel paper substrate was prepared.

Guanidine phosphate (product name: Nonen (registered trademark) 985, manufactured by Marubishi Yuka Kogyo Co., Ltd.) and urethane resin (product name: SuperFlex 150 (product name) ) And Daiichi Kogyo Seiyaku Co., Ltd.) were contained in an amount of 3% by mass and 1% by mass, respectively, based on the entire flame-retardant paper to obtain a flame-retardant paper having a basis weight of 104 g / m ² . The mass ratio of guanidine-based flame retardant to urethane resin (flame retardant / urethane resin) was 70/30. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was six).

[Example 2]
A flame-retardant paper having a basis weight of 104 g / m ² was obtained in the same manner as in Example 1 except that the pulp of Example 1 was changed to 20% by mass and the aluminum hydroxide was changed to 61% by mass. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was seven).

[Example 3]
A flame-retardant paper having a basis weight of 104 g / m ² was obtained in the same manner as in Example 1 except that the pulp of Example 1 was changed to 30% by mass and the aluminum hydroxide was changed to 51% by mass. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was 9).

[Example 4]
In the same manner as in Example 1 except that the pulp of Example 1 was 21% by mass, the aluminum hydroxide was 62.5% by mass, the guanidine-based flame retardant was 1.0% by mass, and the urethane resin was 0.5% by mass. Thus, a flame-retardant paper having a basis weight of 102 g / m ² of Example 4 was obtained. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was 9).

[Example 5]
Except that the pulp of Example 1 was 19% by mass, the aluminum hydroxide was 59% by mass, the guanidine-based flame retardant was 5% by mass, and the urethane resin was 2% by mass, the basis weight of Example 5 was changed. A flame retardant paper having an amount of 107 g / m ² was obtained. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was 5 times).

[Example 6]
Example 6 was repeated in the same manner as in Example 5 except that the pulp was 17% by mass, the aluminum hydroxide was 54% by mass, the glass fiber was 12% by mass, and the guanidine-based flame retardant was 15% by mass. A flame-retardant paper having a basis weight of 117 g / m ² was obtained. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 88/12. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was three).

[Example 7]
The basis weight of Example 7 was 103 g / m in the same manner as in Example 2 except that the pulp of Example 2 was 21% by mass, the aluminum hydroxide was 60.7% by mass, and the urethane resin was 0.3% by mass. ² was obtained. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 90/10. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was 5 times).

Example 8
A flame-retardant paper having a basis weight of 104 g / m ² of Example 8 was obtained in the same manner as in Example 2 except that the guanidine-based flame retardant was 2% by mass and the urethane resin was 2% by mass. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 50/50. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was 13).

[Example 9]
The basis weight of Example 9 was the same as Example 2 except that the aluminum hydroxide of Example 2 was 63% by mass, the guanidine-based flame retardant was 0.2% by mass, and the urethane resin was 1.8% by mass. 102 g / m ² of flame retardant paper was obtained. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 10/90. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). Further, the burning speed of the member bonded to the polystyrene foam was low, and the member passed UL94 HBF (evaluation was ○). In addition, the breakability was also good (the number of breaks was 20 or more).

[Example 10]
Except that the aluminum hydroxide of Example 6 was 54.4% by mass, the glass fiber was 13% by mass, and the urethane resin was 0.6% by mass, the basis weight of Example 10 was 116 g / to obtain a flame燃紙of m ^2. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 96/4. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was good (the number of breaks was two).

[Example 11] The procedure of Example 2 was repeated, except that the guanidine-based flame retardant of Example 2 was guanylurea phosphate (product name: Apinone-405 (trade name), manufactured by Sanwa Chemical Co., Ltd.). A flame-retardant paper having a basis weight of 104 g / m ² of Example 10 was obtained. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 70/30. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 1 shows the results. The burning speed of the flame-retardant paper was low, and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrene foam was low, and the member passed UL94 HBF (evaluation: ◎). In addition, the breakability was also good (the number of breaks was six).

  Table 1 shows the configurations and evaluation results of the flame retardant papers of Examples 1 to 11.

[Comparative Example 1]
Example 1 was repeated except that the pulp of Example 1 was 5% by mass and the aluminum hydroxide was 76% by mass. However, stable production was not possible, and the flame-retardant paper of Comparative Example 1 was not obtained. .

[Comparative Example 2]
Flame retardant of Comparative Example 2 having a basis weight of 104 g / m ^{2 in} the same manner as in Example 1 except that the pulp of Example 1 was 40% by mass, the aluminum hydroxide was 36% by mass, and the glass fiber was 20% by mass. I got the paper. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 70/30. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was high, and it failed UL94 V-0 (evaluation is x). In addition, the burning speed of the member bonded to the polystyrene foam was high, and the material failed UL94 HBF (the evaluation was x). The breaking property was good (13 times), and the flame-retardant paper was excellent in breaking property.

[Comparative Example 3]
A flame-retardant paper having a basis weight of 100 g / m ² of Comparative Example 3 was prepared in the same manner as in Example 2 except that 65% by mass of the aluminum hydroxide of Example 2 and no guanidine-based flame retardant and urethane resin were contained. Obtained. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ◎). On the other hand, the burning rate of the member bonded to the polystyrene foam was high, and the member failed UL94 HBF (evaluation: x). The breaking property was good (20 times or more), and the flame-retardant paper was excellent in breaking property.

[Comparative Example 4]
A flame-retardant paper having a basis weight of 108 g / m ² of Comparative Example 4 was obtained in the same manner as in Example 5 except that the amount of aluminum hydroxide and the urethane resin in Example 5 were 58% by mass and 3% by mass, respectively. The mass ratio of guanidine flame retardant to urethane resin (guanidine flame retardant / urethane resin) was 63/37. Papermaking productivity was rated B because urethane resin adhered to coating equipment and drying rolls.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ◎). Further, the burning speed of the member bonded to the styrofoam was low, and the member passed UL94 HBF (evaluation is ○). The breaking property was good (6 times), and the flame-retardant paper was excellent in breaking property.

[Comparative Example 5]
Except that the pulp of Example 6 was 17% by mass, the aluminum hydroxide was 53% by mass, and the guanidine-based flame retardant was 16% by mass, the same procedure as in Example 6 was carried out, except that the basis weight of Comparative Example 5 was 118 g / m ² . Obtained flame retardant paper. The mass ratio of guanidine-based flame retardant to urethane resin (guanidine-based flame retardant / urethane resin) was 89/11. Papermaking productivity was evaluated as B because the flame-retardant paper was broken during drying in the chemical application step such as impregnation or application and during secondary processing such as slitting or printing.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrofoam was low, and the member passed UL94 HBF (evaluation is ◎). The breakability was poor (twice), and the flame retardant paper was inferior in the breakability.

[Comparative Example 6]
Except that the pulp of Example 6 was 21% by mass, the aluminum hydroxide was 61% by mass, the glass fiber was 15% by mass, and the urethane resin was not contained, the basis weight of Comparative Example 6 was 115 g in the same manner as in Example 6. / M ² of flame retardant paper. Papermaking productivity was evaluated as B because the flame-retardant paper was broken during drying in the chemical application step such as impregnation or application and during secondary processing such as slitting or printing.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ◎). On the other hand, the burning rate of the member bonded to the polystyrene foam was low, and the member passed UL94 HBF (evaluation was ◎). The breakability was poor (1 time), and the flame retardant paper was inferior in the breakability.

[Comparative Example 7]
Comparative Example 7 was prepared in the same manner as in Example 8 except that the pulp of Example 8 was 19% by mass, the aluminum hydroxide was 65% by mass, the glass fiber was 14% by mass, and the guanidine-based flame retardant was not contained. A flame retardant paper with an amount of 102 g / m ² was obtained. Papermaking productivity was rated A.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ○). On the other hand, the burning rate of the member bonded to the polystyrene foam was high, and the member failed UL94 HBF (evaluation: x). The breaking property was good (20 times or more), and the flame-retardant paper was excellent in breaking property.

[Comparative Example 8]
Except that the pulp of Example 6 was 18% by mass, the aluminum hydroxide was 59% by mass, and the flame retardant was a polyborate (product name SOUFA (trade name) and no urethane resin were included, the same as Example 6) Thus, a flame-retardant paper having a basis weight of 110 g / m ² was obtained in Comparative Example 8. The papermaking productivity was such that the flame-retardant paper was dried during the chemical application step such as impregnation and coating, and during the secondary processing such as slitting and printing. Since the paper was broken, the evaluation was B.

  The obtained flame retardant paper was evaluated. Table 2 shows the results. The burning speed of the flame-retardant paper was low and passed UL94 V-0 (evaluation is ◎). In addition, the burning speed of the member bonded to the styrofoam was low, and the member passed UL94 HBF (evaluation is ◎). The breakability was poor (1 time), and the flame retardant paper was inferior in the breakability.

  Table 2 shows the configurations and evaluation results of the flame retardant papers of Comparative Examples 1 to 8.

  In Examples 1 to 11, it was possible to obtain a flame-retardant paper excellent in flame retardancy of flame-retardant paper, flame retardancy of a member obtained by laminating the flame-retardant paper and styrene foam, breakability, and papermaking productivity. .

  On the other hand, in Comparative Example 1, stable production could not be performed. Further, Comparative Example 2 was excellent in the breakability, but was inferior in the flame retardancy of the flame-retardant paper and the bonded product. Comparative Example 3 was excellent in the fracturing property and the flame retardancy of the flame retardant paper, but was inferior in the flame retardancy of the bonded product. In Comparative Example 4, although the flame retardancy of the flame-retardant paper and the bonded product were excellent and the breakability was excellent, the papermaking productivity was poor. Comparative Examples 5 and 6 were excellent in the flame retardancy of the flame-retardant paper and the bonded product, but were inferior in the breakability and the papermaking productivity. In Comparative Example 7, although the flame retardancy of the flame-retardant paper was excellent, the flame retardancy of the bonded product was poor. Comparative Example 8 was excellent in flame retardancy of the flame-retardant paper and the bonded product, but was inferior in foldability and papermaking productivity.

Claims (3)

Pulp, aluminum hydroxide, a flame retardant paper containing a guanidine-based flame retardant and urethane resin, for the flame retardant paper,
The content of the pulp is 10 to 35% by mass,
The content of the aluminum hydroxide is 40 to 70% by mass,
The content of the guanidine-based flame retardant is 0.1 to 15% by mass,
Flame-retardant paper having a urethane resin content of 0.1 to 2% by mass.   The flame-retardant paper according to claim 1, wherein a mass ratio of the guanidine-based flame retardant to the urethane resin (guanidine-based flame retardant / urethane resin) is 50/50 or more and 95/5 or less. A method for producing flame-retardant paper, comprising:
The pulp and the aluminum hydroxide are wet-processed so that the pulp content with respect to the flame-retardant paper is 10 to 35% by mass and the aluminum hydroxide content with respect to the flame-retardant paper is 40 to 70% by mass. A step of obtaining a flame-retardant paper substrate by making paper,
A guanidine-based flame-retardant is used in such a manner that the content of the guanidine-based flame retardant in the flame-retardant paper is 0.1 to 15% by mass and the content of the urethane resin in the flame-retardant paper is 0.1 to 2% by mass. Applying a flame retardant and a urethane resin to the flame retardant paper substrate in this order.