JPH03199500A - Production of flame retardant paper for backing vinyl wallpaper - Google Patents

Abstract

PURPOSE:To prevent black spots due to sticking of iron from occurring and obtain the subject flame retardant paper of high merchandise value by adding aluminum sulfate to wood pulp with a high content of pulp blended therein, adding a specific filler to the resultant slurry, forming sheets of paper under neutral conditions and subjecting the formed paper to flame retardant treatment. CONSTITUTION:Aluminum sulfate is added to wood pulp with a high content of 5-50wt.% pulp (e.g. ground pulp) blended therein and a filler such as (A) aluminum hydroxide blended with a small amount of calcium carbonate, (B) a system of a titanium dioxide and talc, etc., together blended with a small amount of calcium carbonate and (C) a system of titanium dioxide, talc and aluminum hydroxide together blended with a small amount of calcium carbonate, etc., is added to the resultant slurry. A yield improver, etc., are further added and sheets of paper are formed under neutral conditions and impregnated with a mixture solution composed of a flame retardant, binder, surface size, etc., and dried to afford the objective flame retardant paper.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a flame-retardant paper used for lining vinyl wallpaper, and in particular a method for producing flame-retardant paper for lining vinyl wallpaper that reduces the occurrence of black spots due to glue during installation. It is related to.

[Conventional technology]

Flame-retardant paper is widely used as a base paper for various types of wallpaper, and is particularly used as a backing for vinyl wallpaper.

Vinyl chloride wallpaper, which is a typical type of vinyl wallpaper, is manufactured by applying vinyl chloride paste to the surface of flame-retardant backing paper, gelling the vinyl paste by heating, and completing processes such as printing, embossing, and foaming. ing.

Currently, flame retardant paper for vinyl wallpaper lining is generally made of wood pulp,
It is manufactured by impregnating flame retardants and other chemicals into a paper web obtained by making a slurry in a paper machine using titanium dioxide, a combination of titanium dioxide and talc or clay, or aluminum hydroxide as a filler, and then drying it. However, especially when using titanium dioxide, the pH of the slurry entering the paper machine can be adjusted to 4 to 6 by adding sulfuric acid.
It is customary to make the front and rear acidic sides to promote the fixation of papermaking chemicals such as wet paper strength enhancers to the pulp, and to improve the yield and dewatering performance in the wire part of the paper machine.

[What does invention try to solve? S title]

The inventors have discovered that these vinyl wallpapers using flame-retardant paper made on the acidic side and blended with high-yield pulp as backing paper have serious drawbacks. In other words, if foreign matter containing iron gets mixed in or adheres to the surface of the lining paper during the paper making process or the subsequent PVC processing process, the diameter of the lining paper may change when the lining paste is applied and left unattended during the construction of wallpaper products. This is the occurrence of conspicuous black to gray speckled spots (hereinafter abbreviated as black spots) of 1 to 10 nn.

Incidentally, in recent paper bonding work, gluing and pasting have been divided into labor groups, and it is no longer uncommon for the gluing to be left for several hours or even over a day or night, and problems caused by the appearance of black spots have become less common. It's coming to the surface.

When such black spots occur, they may be identified as stains on the surface of the wallpaper (PVC surface) after installation, or may be mistaken as mold, which significantly impairs its commercial value.

The object of the present invention is to prevent the occurrence of black spots as much as possible.

[Means to solve the problem]

The inventors of the present invention have conducted extensive research to solve this problem, and have developed a vinyl wallpaper that uses flame-retardant paper as a backing paper, which is blended with high-yield pulp, added with sulfuric acid, and made on the acidic side. The present invention was achieved by discovering that the problem could be solved by using a specific filler in combination with the pulp slurry.

High-yield pulps include crushed ice pulp (AP), thermomechanical pulping ground pulp (R-GP), chemical ground pulp (C-GP), and chemical thermomechanical pulp (C-GP).
TMP) is used because these formulations are extremely effective in imparting functions such as hiding properties, smoothness, and stiffness required to flame-retardant paper for backing vinyl wallpaper.

The present invention will be explained in detail below.

(A) When the filler is a mixture of aluminum hydroxide and a small amount of calcium carbonate; Aluminum hydroxide exhibits a flame retardant effect by releasing crystal water when burned, so flame retardant paper for vinyl lining is used. It is suitable as a filler.

In this case, by adding some calcium carbonate to the aluminum hydroxide used as a filler, the slurry p)l after being added to the pulp changes from acidic to alkaline,
The attached iron can be converted into water-insoluble compounds such as iron hydroxide.

Furthermore, by adding calcium carbonate, it is also possible to capture sulfate ions, which promote the production of water-soluble iron compounds, as poorly water-soluble calcium sulfate.

If the amount of calcium carbonate used is 1% by weight or more in the paper, the effect will be sufficiently exhibited.

As the calcium carbonate used in the present invention, light or heavy calcium carbonate in a variety of slag-treated shapes can be used, but spindle-shaped light calcium carbonate is particularly preferred.

(B) When a small amount of calcium carbonate is added to titanium dioxide or a system using it in combination with talc or clay as a filler; titanium dioxide is used for the m-twisted string for backing vinyl wallpaper.

Alternatively, acid-made flame-retardant paper using a combination of titanium dioxide and talc or clay is widely used.

Titanium dioxide is used because its use significantly improves the hiding properties required for flame retardant paper for backing vinyl wallpaper.

(C) When a combination system of titanium dioxide, talc, and aluminum hydroxide is used as a filler, with a small amount of calcium carbonate added; Aluminum hydroxide may also be added to this system for the purpose of imparting flame retardancy. can.

The same method of preventing black spots by adding calcium carbonate as shown in the case of filler (A) can also be applied to this system.

(D) When using a combination of titanium dioxide and a small amount of sodium hydroxide or calcium hydroxide as a filler; In the case of titanium dioxide-containing paper produced by acid papermaking, the mixed slurry of pulp, filler, and other substances introduced into the paper machine is The occurrence of black spots can also be prevented by adjusting the pH from around normal to slightly alkaline. Suitable alkalis for pHvjI4W include sodium hydroxide, calcium hydroxide, and ammonia water.

The one-pass yield of pulp and filler in the wire part of the paper machine decreases slightly due to pH adjustment, but there is no problem if a polymeric yield improver such as cationic polyacrylamide, polyamide epichlorohydrin resin, or polyacrylamide is used.

The method of imparting flame retardance in the present invention is distantly related to impregnating a paper web with a size press machine or the like with a mixed aqueous solution mainly consisting of a flame retardant, a binder, a surface sizing agent, etc., and drying the same.

As the flame retardant, guanidine sulfamate, methylolated derivative thereof, ammonium sulfamate, guanidine phosphate, etc. are used, and they may be used alone or in combination of two or more.

As the binder, polyvinyl alcohol, starch or a modified product thereof, carboxymethyl cellulose, or a synthetic resin emulsion may be used alone or in combination of two or more.

In addition, dicyandiamide, methylolated melamine, dyes, antifoaming agents, paper strength improvers, and the like may be used in combination as surface sizing agents and discoloration inhibitors.

The amount of these mixed solutions applied is 10 to 50% solid content per flame retardant paper product. Preferably, 10 to 30% by weight is appropriate, and the target application amount can be obtained depending on the concentration of the liquid.

If the amount applied is less than the appropriate amount, self-extinguishing properties, which are the basic characteristics of flame-retardant paper, will not be obtained, and if it is applied in excess, quality such as strength and stiffness will deteriorate and it will be uneconomical.

[Effect]

This phenomenon occurs when water-based glue such as starch is applied to the backing paper surface for construction, and sulfate ions are generated from flame retardants such as sulfuric acid band and guanidine sulfamate, which are used to make flame-retardant paper. However, it reacts with iron-containing foreign substances attached to the base paper to produce water-soluble iron compounds such as ferrous sulfate, and reacts with lignin or extracted components mainly present in the high-yield pulp of the backing paper, producing a black color. It is thought to produce spots. For example, it is well known that phenol components present in lignin easily react with iron ions to produce black complex compounds.

The present inventors focused on the fact that the formation of black spots is due to the reaction between water-soluble iron compounds and lignin or extracted components, and by converting the attached iron to water-insoluble compounds, the black spots that conventional backing paper had We succeeded in eliminating the factors that caused this.

〔Example〕

Hereinafter, the content of the present invention will be explained in more detail with reference to Examples. The test method followed the method shown below.

1. Basis weight Measured according to JIS P-8124 2. Filler content in paper After burning the paper web at 900°C, the weight of the remaining filler was measured and expressed as a percentage of the weight before burning.

3. Evaluation of black spots Dilute starch-based Yayoi Kagaku A glue 3 times with water.
It is applied to the surface of M-burning paper with a brush, and iron powder scraped from a common material such as a carbon steel plate is sprinkled on top of it. After that, cover it with a polyethylene sheet and leave it in a wet state for 1 day and night, and then check whether there are black spots that occur around the iron powder.
Inspect and confirm.

Example 1 A sulfuric acid band is applied to a pulp consisting of 50 parts by weight of N-BKP, 20 parts by weight of L-BKP, and 30 parts by weight of GP]
, Q heavy region, polyamide epichlorohydrin resin (manufactured by Dick Vercules, trade name Kaimen 557)
0.4 parts by weight of H) was added.

Aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., C-301) with a center particle diameter of 1.0 mm was added to this slurry as a filler for 20 minutes.
In the overlaying section, 1 part by weight of light calcium carbonate (manufactured by Okutama Kogyoku, Tamapearl 121), and finally 50 ppm of high-molecular polyacrylamide resin (manufactured by Sento Kagaku ■, trade name Polymaster R-623) as a retention improver. In addition, paper was made using a Fourdrinier paper machine to obtain a paper web of 59 g/rri.

Next, guanidine sulfamate 1 manufactured by Sanphase Chemical ■
00 parts by weight of polyvinyl alcohol, 5 parts by weight of surface sizing agent, and 5 parts by weight of methylolmelamine. flame retardant paper was obtained.

Example 2 N-BKP 50 parts by weight, L-BKP 20
8 parts by weight of titanium dioxide and 1 part by weight of calcium carbonate were added as fillers to a slurry obtained by adding the same papermaking chemicals and retention improver as in Example 1 to pulp consisting of 30 parts by weight of TMP and 30 parts by weight of TMP, and paper was made using a Fourdrinier paper machine. Yes, 57g
/I got Bo's paper animal.

Next, the paper web was impregnated with an aqueous solution having the same liquid composition as in Example 1 and a concentration of 28% by the size press method, and then dried to obtain a flame-retardant paper of 10 g/rl.

Example 3 8 parts by weight of titanium dioxide as a filler and sodium hydroxide as an alkali were added to a slurry made by adding the same papermaking chemicals to the same pulp as in Example 2 to adjust the pH to 765, and paper was made using a Fourdrinier paper machine. , 57 g/bo of paper was obtained.

Next, the paper web was impregnated with a 28% aqueous solution having the same liquid composition as in Example 1.2 by a size press method, and then dried to obtain a 10 g/rd flame retardant paper.

Comparative Example 1 The same pulp and papermaking chemicals as in Example 1 were used, but 20 parts of aluminum hydroxide alone was added as a filler for papermaking to obtain a paper web of 59 g/rr.

Next, the paper web was impregnated with a 22% aqueous solution having the same liquid composition as in the example by the size press method, and then dried to give a 1.
A flame retardant paper of 0 g/m was obtained.

Comparative Example 2 The same pulp and papermaking chemicals as in Example 2 were used, but 8 parts of titanium dioxide alone was added as a filler for papermaking.
A paper web of g/m was obtained.

Next, the paper web was impregnated with an aqueous solution having the same liquid composition as that on the downstream side and a concentration of 28% by the size press method.

After drying, a flame retardant paper weighing 70 g/rri' was obtained.

Comparative example 3 N-13K P 60 heavy electric range, L -B K P
The same papermaking chemicals as in the example were added to the pulp consisting of 40 parts by weight, and 10 parts by weight of titanium dioxide alone was added to make paper, resulting in a paper-making product of 57 g/n? I got a paper fish.

Next, the paper web was impregnated with a 28% aqueous solution having the same liquid composition as in the example by the size press method, and then dried to give a
A flame retardant paper of 0 g/rrr was obtained.

The slurry compositions and properties of the flame-retardant papers of these Examples and Comparative Examples are shown in Tables.

The following margin [Effects of the invention] In the conventional manufacturing method of flame-retardant paper shown in Comparative Examples 1 and 2 in the table, iron adhesion was detected in both aluminum hydroxide-containing paper and titanium dioxide-containing paper during the check at the base paper stage before PVC processing. This indicates that there is a high risk of black spots occurring during construction due to the adhesion of foreign substances containing iron during PVC processing.

Although black spots did not occur in Comparative Example 3, which did not use high-yield pulp, it lacked the thickness and hiding properties required for flame-retardant paper for lining vinyl wallpaper, making it unsuitable as lining paper. there were.

On the other hand, in Examples 1 and 2.3, no black spots due to adhesion of iron were observed, and the effects of the present invention are certain.

Regarding the quality of flame retardant paper such as flame retardant performance, strength, hiding property, and suitability for PVC processing, see Example 1, Comparative Example 1, and Example 2.
．． There was almost no difference between Comparative Example 3 and Comparative Example 2.

As described above, we have discovered a serious drawback of conventional flame-retardant paper for vinyl wallpaper lining in response to the problem of black spots that have surfaced as a result of changes in wallpaper construction work, and we have developed the present invention to eliminate this problem. It is of great significance that we have established a manufacturing method for lining paper that prevents this from occurring.

Claims (1)

[Claims] 1. A slurry made by adding sulfuric acid to wood pulp containing 5 to 50% by weight of high-yield pulp, using one of the following as a filler and paper-making under neutral conditions, A method for producing flame-retardant paper for lining vinyl wallpaper, which is characterized by subjecting it to flame-retardant treatment, (A) aluminum hydroxide mixed with a small amount of calcium carbonate, (B) titanium dioxide or a combination of talc or clay A system containing a small amount of calcium carbonate, (C) a combination system of titanium dioxide, talc, and aluminum hydroxide, and a small amount of calcium carbonate, (D) titanium dioxide and a trace amount of sodium hydroxide, or Combined with calcium hydroxide.