JPH04272991A - Flameproofing agent - Google Patents

Abstract

PURPOSE:To obtain a flameproofing agent improved in storage stability by using a sulfonated melamine resin as a melamine resin in a flameproofing agent based on a sulfamic acid salt which contains the melamine resin. CONSTITUTION:An aqueous solution of guanidine sulfamate is mixed with an aqueous solution of a precondensate of a melamin resin containing a sulfone group which is obtained by reacting melamine, sodium hydrogen sulfite and formaldehyde, in place of conventional aqueous melamine resin solutions. The melamine resin containing a sulfone group is easily soluble in the aqueous guanidine sulfamate solution even after longterm storage in summer. Further, a highly concentrated aqueous solution of the two components can be stored for a long period of time as a one-pack flameproofing agent.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame retardant, and more particularly to a flame retardant suitable for use in cellulose fibers and paper.

0002

[Prior Art] Sulfamate-based flame retardants such as guanidine sulfamate are used for cellulose-based materials such as cellulose fiber cloth, paper such as wallpaper, fusuma paper, shoji paper, paperboard, and even wood. It is used for flame retardant processing. In particular, wall covering materials such as wallpaper are often coated with a sol coating of vinyl chloride resin, etc., and this coating process involves heat treatment at about 200°C for about 1 to 2 minutes, but sulfamine Wall covering materials treated with acid-based flame retardants have common problems such as thermal discoloration or loss of strength during this heat treatment.

[0003] To this end, a method of adding a water-soluble melamine resin, which is one of the triazine resins, to the flame retardant component as an additive having thermal discoloration prevention properties, a so-called thermodiscoloration inhibitor, has been proposed in Japanese Patent Application Laid-open No. It was proposed in No. 125395/1983.

0004

[Problems to be Solved by the Invention] However, water-soluble melamine resins such as melamine-formaldehyde reaction products and melamine-formaldehyde-alcohol reaction products described in the above publications undergo polycondensation during storage. Because of this tendency, the water solubility decreases over time, making it difficult to add and dissolve in a guanidine sulfamate aqueous solution.

[0005]

[Means for Solving the Problems] The present inventors have made extensive studies in view of the above problems, and have found that when a triazine resin having a sulfone group is used as the triazine resin,
It has been found that the above-mentioned problems can be solved without impeding flame retardancy, and the present invention has been completed.

That is, the present invention provides a flame retardant comprising a sulfamate and a triazine resin, characterized in that a triazine resin having a sulfone group is used as the triazine resin. be.

[0007] The sulfonic group in the present invention refers to a sulfonic acid group and a water-soluble sulfonate group. As the base used for forming the sulfonate, any known and commonly used base can be used, including alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, monoamines such as methylamine and ethylamine, dimethylamine, Examples include diamines such as diethylamine, triamines such as triethylamine and trimethylamine, and ammonia.

[0008] The triazine resin having a sulfone group in the present invention refers to a synthetic resin having both a triazine skeleton and the above-mentioned sulfone group, and includes, for example, a melamine resin, a benzoguanamine resin, and an acetoguanamine resin.

[0009] The method for producing the triazine resin having a sulfone group is not particularly limited, but a common method is, for example, to react a triazine, an aldehyde, and a sulfite.

[0010] Examples of the triazines used here include melamine, acetoguanamine, benzoguanamine, etc. Among them, melamine is preferred. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, etc., with formaldehyde being particularly preferred. Commercially available industrial formalin and paraformaldehyde can also be used.

Examples of sulfites include sodium sulfite, ammonium sulfite, sodium hydrogen sulfite, ammonium hydrogen sulfite, and sodium pyrosulfite.

Furthermore, alcohols such as methanol and butanol may be used in combination, if necessary. The conditions for producing the triazine resin having a sulfone group are not particularly limited, and any known conditions can be employed. Hereinafter, conditions for producing a melamine resin, which is preferable among the triazine resins used in the present invention, will be illustrated and explained.

[0013] The melamine resin contains triazines containing melamine as an essential component, and 0.8 to 1.2 moles of formaldehyde and 0.3 to 0.4 moles of sulfites per mole of amino group.
mol in an aqueous medium at a pH of 9 to 13 and a temperature of 50 to 80°C for 30 to 120 minutes. The melamine resin obtained in this way is
Mononuclear triazine rings account for 80% by weight or more of the total solid content.

[0014] Furthermore, when preparing a flame retardant for the purpose of performing flameproofing and stiffening at the same time, it is preferable to use a high polycondensation type melamine resin as the stiffening agent. The highly polycondensed melamine resin is preferably one in which the total of triazine rings having a degree of polycondensation of two or more constitutes the main solid component.

[0015] The method for producing the highly polycondensed melamine resin is not particularly limited;
Adjust H to 4 to 6, and further heat to 30 to 60℃ at a temperature of 40 to 60℃.
It can be produced by heating for 300 minutes, adjusting the pH to 8 to 13, and cooling. When producing melamine resins, it is better to increase the degree of condensation as much as possible without reducing water solubility, storage stability, or solubility in sulfamate aqueous solutions, which are the main ingredients of flame retardants, when used for this purpose. preferable.

The method for controlling the degree of polycondensation of the melamine resin to an appropriate level is not particularly limited, and any known method may be used. For example, there is a method of controlling by the viscosity of the aqueous solution. The lower the viscosity of the melamine resin aqueous solution, the easier it is to dissolve in the sulfamate aqueous solution.

When the melamine resin according to the present invention is used for the stiffening process, the solid content of the melamine resin is 3
The viscosity of a 5% by weight aqueous solution at 25°C is about 20-300
It is preferable to set it to approximately CPS, and when used for other purposes, it is preferable to set it to 20 CPS or less.

Further, the pH regulator used in the above reaction is not particularly limited, but includes, for example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphoric acid mono- or dialkyl ester, sulfamic acid, oxalic acid, maleic acid, maleic anhydride, Examples include acids such as maleic acid monomethyl ester and alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

The triazine resin according to the present invention may be one obtained by co-condensing a co-condensation component other than triazines. However, those condensed with triazines as the main component are preferred.

The cocondensation component that can be used in the above cocondensation is not particularly limited, but examples thereof include urea, thiourea, ethyleneurea, guanylurea, dicyandiamide, and functional derivatives thereof.

The triazine resin according to the present invention may be a melamine resin, a benzoguanamine resin, or an acetoguanamine resin, which may be used alone or in combination of two or more. Of course,
The triazine resin according to the present invention may be used in combination with a known and commonly used condensation synthetic resin, if necessary. Known and commonly used condensation synthetic resins that can be used in this case include, for example, urea resins, melamine resins, phenol resins, and the like.

[0022] Suitable known and commonly used melamine resins that can be used in combination with the melamine resin according to the present invention are:
Examples include melamine resins in which part or all of the terminal hydrogen atoms of the methylol groups contained in the structure are substituted with alkyl groups. Examples of such melamine resins include methoxymethylmelamine resins and butoxymethylmelamine resins.

[0023] Examples of the sulfamate salt, which is another essential component of the flame retardant of the present invention, include guanidine sulfamate. The sulfamate salt may also contain small amounts of other impurities. Commercially available guanidine sulfamate usually contains small amounts of other impurities. Examples of such impurities include ammonium sulfamate, dicyandiamide, diammonium imidodisulfonate, ammonium guanidine imidodisulfonate, diguanidine imidodisulfonate, melamine, ammeline, guanylurea, and the like. However, it is preferred to use highly purified guanidine sulfamate with as few impurities as possible, for example, the total amount of impurities is less than about 20% by weight, preferably less than 10% by weight of the total weight.

The method for producing the sulfamate salt of the present invention is not particularly limited. The method for producing guanidine sulfamate, which is the most suitable sulfamate according to the present invention, will be explained as an example.

Guanidine sulfamate can be easily produced by reacting ammonium sulfamate and dicyandiamide using a known and conventional method. In that case, ammonium sulfamate and dicyandiamide may be melt-reacted at, for example, 140 to 180°C. The composition of the reaction product varies depending on the reaction molar ratio of ammonium sulfamate and dicyandiamide, but unless special purification is performed, it often contains small amounts of impurities in addition to guanidine sulfamate.

Further, as the sulfamate according to the present invention, a reaction product of guanidine sulfamate and formaldehyde can also be used. The guanidine sulfamate used in this case is also preferably guanidine sulfamate with as high a purity as possible. The method for producing the reaction product of guanidine sulfamate and formaldehyde is not particularly limited, and can be produced by any known method. For example, formaldehyde is 0.05 to 1.0% per mole of guanidine sulfamate.
It can be produced by heating 2 mol in an aqueous medium at a temperature of 40 to 80°C for 20 to 200 minutes.

The components of the flame retardant in the present invention, ie, the sulfamate salt and the triazine resin having a sulfone group, may be used in combination when performing flame retardant treatment, but the above two components may be mixed in advance. It can also be handled in the form of a highly concentrated aqueous solution. Furthermore, a triazine resin containing no sulfone group may be used in combination.

The amount of the triazine resin used in the present invention is 0.5 parts by weight or more, preferably 1.0 parts by weight or more, based on 100 parts by weight of the sulfamate. The amount of the triazine resin according to the present invention can be changed depending on the purpose of use. For example, when used as a thermochromic inhibitor, sulfamate 1
0.5 parts by weight or more, preferably 1.0 parts by weight
It is used in an amount of 2.0 parts by weight or more, preferably 3.0 parts by weight or more when used as a stiffening agent.

The flame retardant of the present invention may contain the above-described sulfamate and a triazine resin having a sulfone group, but if desired, it may contain, for example, a sizing agent, a surfactant, a rust preventive, PH regulator, antifoaming agent, moisture absorption inhibitor,
Other additives such as starch can be added as appropriate.

Furthermore, since the flame retardant of the present invention has excellent compatibility and stability, it can be used in a solution containing both the sulfamate and the triazine resin, for example, with a non-volatile content of 40%.
It can be handled in the form of an aqueous solution. Thus, highly concentrated solutions containing both components can be transported, stored, and otherwise handled. Furthermore, the sulfamate salt and the melamine resin may be handled individually, or the two components may be used as a mixture when flameproofing cellulose fibers or paper.

[0031] The amount of the flame retardant of the present invention attached to the base material is:
The solid content is 10 to 50% by weight, preferably 15 to 35%. Further, the method of attaching the flame retardant of the present invention to the substrate is not particularly limited, and any conventional method may be used. For example, there are a method of spraying a liquid mixture containing the flame retardant of the present invention, a method of applying it with a brush, a method of applying it using a size press, a method of dipping paper into the liquid mixture, and the like.

[0032]

[Examples] The present invention will be explained below with reference to Examples.
This is just one aspect, and the present invention is not limited by the examples.

[0033] All "%" in the text is based on weight. Regarding the samples and reaction materials used in the following examples,
It is abbreviated as follows. SGU: Industrial guanidine sulfamate (purity 92.
3%) SAm/Dd: reaction product of ammonium sulfamate and dicyandiamide in a molar ratio of 2/1 SGu/F: reaction product of industrial guanidine sulfamate and industrial formaldehyde in a molar ratio of 1/0.2 M -MLS: Viscosity of aqueous solution of 35% solid content of high polycondensate resin containing sulfone group and methoxy group: 40.0 cps M-ML
: Viscosity of a 35% aqueous solution of melamine resin containing methoxy groups that does not contain sulfone groups.
Add 5000 grams of % industrial formalin, add 4950 grams of 35% sodium acid sulfite and 2100 grams of melamine under stirring, add 48% aqueous sodium hydroxide solution to adjust the pH to 11.5, and stir for 20 minutes. The reaction mixture was heated to 70°C over 30 minutes.
After reacting for a minute, the mixture was cooled to 55°C.

Further, the pH of the reaction mixture was adjusted to 9.3 using an aqueous solution of hydrochloric acid with a concentration of 18%, and 2200 grams of water was added to give a solid content of 35% and a viscosity of 10c at 25°C.
A sulfone group-containing melamine resin initial condensate of ps was obtained. Hereinafter, this will be referred to as MLS. Synthesis Example 2 As in Synthesis Example 1, 5000 g of 37% industrial formalin was placed in a reaction vessel equipped with a thermometer, stirrer, and condenser, and 495 g of 35% sodium acid sulfite was added to this with stirring.
48% by adding 0g and 2100g of melamine.
A sodium hydroxide aqueous solution was added to adjust the pH to 11.5, and the reaction mixture was heated to 70°C over 20 minutes while stirring, and then allowed to react for 30 minutes, and then cooled to 55°C.

Next, the pH was adjusted to 5.3 using an aqueous solution of hydrochloric acid with a concentration of 18%, and the temperature of the reactants was maintained at 55°C and the condensation reaction was carried out for 3 hours with stirring. Immediately, 48% sodium hydroxide was added. Adjust the pH to 9.2 using an aqueous solution,
Add 1780 grams of water, solid content concentration 35%, 25%
A sulfone group-containing melamine resin high polycondensate having a viscosity of 80 cps at °C was obtained. Hereinafter, this will be referred to as P-MLS. Examples 1 to 7 and Comparative Examples 1 to 2 Table-1
Melamine resin with a solid content concentration of 35% that had been aged at 35°C for 30 days was added to a sulfamate aqueous solution with a solid content concentration of 30% in an amount of 1% or 5% in terms of solid content, and its solubility was investigated. Show the results. Note that all melamine resins maintained good water solubility after aging at 35° C. for 30 days.

As for the solubility evaluation method, when the mixed solution had a transparent appearance, it was evaluated as "good", and when it was cloudy, it was evaluated as "poor". It can be seen that the sulfonic group-containing melamine resin maintains its solubility in the sulfamate aqueous solution even after being aged at high temperatures.

[0037]

[Table 1]

[0038] Examples 8 to 10 and Comparative Example 3 Table -
2, melamine resin with a solid content of 5% was added to the sulfamate, and an aqueous solution prepared to a solid content concentration of 50% was added to 35% of the solid content.
The results of examining the water solubility after aging at ℃ for 30 days are shown.

[0039] Regarding the water solubility evaluation method, when mixed in twice the amount of water, a product with a transparent appearance was rated as "good", and a product with a cloudy appearance was rated as "poor". The cloudy product gradually formed a precipitate. The mixed liquid containing sulfone group-containing melamine resin is
It can be seen that it maintains excellent water solubility even after being aged at high temperatures. In comparison, it can be seen that a mixed solution containing a melamine resin containing no sulfone group loses water solubility and is not suitable for practical use.

[0040]

[Table 2]

Examples 11 to 12 and Comparative Example 4 Table 3 shows the results obtained by processing wallpaper base paper using a flame retardant containing sulfamate and adding the amount of melamine resin listed in the table. The results of an investigation into the thermal discoloration prevention properties of flame-retardant treated paper are shown below. Note) "Amount of melamine resin added" in the table indicates the percent solid content relative to sulfamate.

[0042] The thermal discoloration prevention property was evaluated by heat-treating the obtained flame-retardant treated paper at 200°C for 1 minute and expressing the whiteness obtained using a Hunter whiteness meter. ``〇'' means that the thermal discoloration prevention effect is clearly recognized, and ``〇'' means that the effect of preventing thermal discoloration is clearly recognized.
△", and those with particularly low whiteness were rated "x".

From the results in Table 3, it can be seen that the flame retardant of the present invention is clearly effective in preventing thermal discoloration.

[0044]

[Table 3]

[0045]

Effects of the Invention Melamine-based resins having a sulfone group and a triazine skeleton can maintain solubility in aqueous sulfamate solutions even after long-term storage in summer, and a highly concentrated aqueous solution containing the two is It can also be stored for a long period of time as a one-component flame retardant containing a heat discoloration inhibitor or a stiffening agent.

Claims (7)

[Claims] [Claim 1] In a flame retardant comprising a sulfamate and a triazine resin, as the triazine resin,
A flame retardant characterized by using a triazine resin having a sulfone group. 2. The flame retardant according to claim 1, wherein the triazine resin is a reaction product of triazines, aldehydes, and sulfites. 3. The flame retardant according to claim 2, wherein the triazine is melamine and the aldehyde is formaldehyde. 4. The flame retardant according to claim 1, wherein the sulfamate is guanidine sulfamate. 5. The flame retardant according to claim 1, wherein the sulfamate is a reaction product of ammonium sulfamate and dicyandiamide. 6. The flame retardant according to claim 1, wherein the sulfamate is a reaction product of guanidine sulfamate and formaldehyde. 7. The flame retardant according to claim 1, which contains 0.5 parts by weight or more of the triazine resin based on 100 parts by weight of the sulfamate.