JPH01304935A - Fire retardant woody material - Google Patents

Abstract

PURPOSE:To improve fire retardancy, humidity resistance and water resistance, by applying a bottom coating agent containing polyvinyl alcohol as an essential component to a woody base material and further applying a water-soluble or water-dispersible condensation type resin thereto. CONSTITUTION:An aqueous solution containing polyvinyl alcohol and/or polyacrylamide as an essential component is applied to a woody base material and, subsequently, a fire retardant coating agent containing a water-soluble or water-dispersible condensation type resin as an essential component is applied thereon to prepare a fire retardant woody material. The obtained fire retardant woody material and decorative paper or woody veneer coated with the aqueous solution containing polyvinyl alcohol and/or polyacrylamide as the essential component being a bottom coating agent are unified so that the coating surface of the fire retardant coating agent of the fire retardant woody material is bonded to the coating surface of the aqueous solution on the decorative paper or woody veneer to form a fire retardant woody material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a flame-retardant wood material having excellent properties.

(Conventional technology) Research has been carried out around the world to improve the flame retardancy of wood building materials as administrative authorities in each country have tightened regulations on the flammability of wood building materials. In the case of plywood, veneers are immersed in flame retardant liquid, seamed after drying, or mixed with adhesive and flame retardant liquid is used to make plywood. ? - There are known methods for producing flame retardant chemicals and methods for applying flame retardant chemicals to wood or plywood.

Flame-retardant wooden building materials obtained by these conventional manufacturing methods have the following characteristics.

, Σ− Flame retardant performance Excellent Excellent Slightly inferior Flame retardant performance Water resistance Excellent Excellent Slightly inferior Delamination of plywood during heating None With reeds Productivity Large Small Medium As mentioned above, K, the painting method is effective in terms of productivity. The most advantageous method, the injection method, which requires a long drying time, has much lower production costs, but is still largely unpractical in the industry. The reasons for this can be considered to be the following points.

b) For example, conventional flame-retardant coating methods have a fire-retardant performance that is sufficient to pass the heating test for flame-retardant edges under the Building Standards Act (JISA1321 flame-retardant class 3), which is applied to interior materials in Japan. What I didn't get.

Since the wood surface to be painted is a natural product, it is non-uniform, so the amount of flame retardant adhesion is not necessarily uniform, and the wood material itself has uneven combustibility, resulting in combustion. Variation in test scores.

c) Partial whitening and opacity often caused by flame retardant formulations containing finely powdered flame retardants such as ammonium polysinate.

2) Occurrence of undesirable gloss when only a reactive flame retardant such as 3-(dimethylphosphono)glopionamide is used in combination with a condensation type synthetic resin.

e) It has been estimated that in order to pass JIS A-1321 flame retardant class 3, it is necessary to apply flame retardant with a solid content of at least 30,017m, From the perspective of painting technology, a coating thickness of around 200?/m" was thought to be the limit.

(Problems to be Solved by the Invention) The present invention has the following features: (1) High degree of flammability and its moisture resistance and performance retention during water resistance (1) Excellent aesthetic appearance and its retention over time (3) During heating in the case of plywood The objective is to provide a flame-retardant wood material with excellent peeling resistance and 2) high productivity.

(Means for Solving Problem 11) The present invention (a) coats a wood substrate with an aqueous solution containing polyvinyl alcohol and/or polyacrylamide as an essential component as a base coating agent, and then coats the base coat with a water-soluble or water-dispersible solution. A flame-retardant wood material coated with a flame-retardant coating agent containing a condensation resin as an essential component; A flame-retardant wood material obtained by bonding a painted decorative paper or wood veneer by bonding the flame-retardant coating surface of the flame-retardant wood material and the aqueous solution applied surface of the decorative paper or wood veneer. and (c
) The above (1) or (2) using an aqueous solution containing polyvinyl alcohol and/or polyacrylamide in combination with melamine resin as an essential component as a base coating agent.
Regarding flame retardant wood materials.

The present invention provides flame retardancy, water resistance, moisture resistance, and
It clearly indicates a very limited range of wood materials that can be manufactured at low cost with excellent aesthetics and durability, and is expected to be rapidly industrialized due to the ease of implementation. be done.

(1) Wooden substrate used in the present invention Wooden substrates used in the present invention include board members, logs, plywood, fiberboards, wafer gates, etc., and are not yet coated with paints or Even if the surface has already been painted, it should still be able to penetrate the flame retardant paint. No matter how much flame retardant paint is used on thin wood substrates, the flame retardant performance will not improve, so it is desirable that the thickness is at least 5 mya or more, usually 9 mya.

(2) Base coating agent and coating method First, an aqueous solution containing an aqueous solution of polyvinyl alcohol or/and polyacrylamide as an essential component is applied as a base coat to the surface of the wood base material to be coated with flame retardant coating. This polyvinyl alcohol has a saponification degree of 98 to 99 molti (completely saponified) or 87 to 8
Which of 9 (partial saponification) or one in between) has an average degree of polymerization of 300 to 700 (low degree of polymerization), or 1
,000 to 1.500 (medium degree of polymerization type) or 1,700
~2.400 (high polymerization degree type) or something in between.Actually, one of the six types of commercially available products that are a combination of a) and a) is used. is convenient. According to the results of experiments, good results can be obtained no matter which type is used, but partially saponified products with high viscosity are easy to dissolve and have a strong film, so they are suitable for mass production. This base coating agent is 1 chill 25%, preferably 5% to
An aqueous solution of 10, for example, 20 to 200? /frL2,
Preferably, the coating amount is 100 to 150117 m''.
b) Parts, boards, logs, etc. are coated using a gray gun, dipping method, brush, or sponge roll coater. In order to prevent repellency due to the presence of oil and resin in the wood base material, a preferable uniform base coating can be achieved by adding a surfactant and an antifoaming agent such as FCB or octyl alcohol. As stated above, the appropriate coating amount of the base coating agent whose main component is polyvinyl alcohol is 0.277 m'' in terms of solid content.
5097m", but the flame retardancy of the final flame-retardant wood base material will be affected somewhat by the amount of coating, as long as the polyvinyl alcohol film is uniformly formed. No. However, the coating amount as a solid content is approximately 5?/ln" to 10. It is preferable to adjust the concentration and coating amount to a range of OiP/m''.

In addition to polyvinyl alcohol, a water-soluble polymer compound that is particularly suitable as a base coating agent is polyacrylamide. Although the ionicity of this polymer compound is nonionic, it can be partially hydrolyzed or copolymerized to introduce sialic acid groups or their salts to form anionic or cationic groups (e.g. dimethylaminomethyl group). Although it may be a cationic form copolymerized with a cationic monomer or an amphoteric form containing both an anionic group and a cationic group, a nonionic form gives the most favorable results. When the main component is polyacrylamide, an aqueous solution having a concentration of about 0.1 to 0.5% and a molecular weight of 100,000 to several million millions gives preferable performance.

The polymer compound used before base coating must be a) water-soluble and form a continuous transparent film upon drying, and (b) a polymer compound with a continuous carbon skeleton. It needs to have the ability to react with synthetic resins to become crosslinked and become water-insoluble.

The base coating agent used in the present invention has a solid content of 1 to 20%.
If the base coating is performed in the presence of a water-soluble melamine resin in an amount of 3 to 8% by weight, preferably 3 to 8% by weight, and an acid catalyst, such as ammonium chloride, the crosslinking of the water-soluble melamine resin will reduce the water solubility of the water-soluble polymer compound. Painting work with flame retardant becomes easier. However, if a large amount of excess water-soluble melamine resin is used, the insolubilization of the base coating film will progress too much, reducing the reactivity with the flame retardant coating agent and reducing the adhesive strength, so it is best to keep it to the minimum necessary amount. is necessary.

The film formed by the base coating agent in the present invention is formed between the wood base material and the flame retardant paint layer, and between the decorative paper or wood veneer and the flame retardant paint layer applied to the wood base material. There is a need to. If an aqueous solution of polyvinyl, It/alcohol or polyacrylamide is mixed with a flame retardant paint, the flame retardant performance will be significantly reduced, so even if the base paint is laminated with the flame retardant paint. For example, after applying a base paint and completely drying, apply a flame retardant paint on top of it, use a flame retardant paint with as high a concentration as possible, and also ensure that polyvinyl alcohol does not dissolve again. It is necessary to dry quickly after painting. In addition, the flame retardant coating agent contains boric acid, which is a chlorinating agent for 4-lipinyl alcohol,
Add a small amount of one or more types of halates and metabalates (
For example, by adding an aqueous solution of 0.01 to 5x*s, or by treating the dry film of the base coating agent with an aqueous solution of these, re-dissolution of the film of the base coating agent can be prevented.

Although the flame retardance is significantly improved by applying the base paint,
Although the reason for this is unknown, it is presumed that it is probably due to the following mechanism.

1) First, it is painted on the surface of a wood base material, dried, and becomes insoluble by reacting with the flame retardant coating agent applied thereon. The effect of blocking flammable gas by forming a foam layer that is soft, highly fluid, and hard to break when heated above about 220°C. However, if flame retardant paint is used alone, the resulting heat insulating layer is hard and cracks easily, and cannot completely block out the eruption of flammable gas, but the presence of the base paint layer makes the heat insulating layer difficult to crack and prevents flammable gas from being emitted. It is thought that the gas is not ignited because it is exhausted little by little from the entire heating surface rather than through the cracks.

11) The wood base material, which is a natural product, is chemically heterogeneous, and the cellulose, which contains about 35 to 65% in terms of solid content, is hardened with hydrophobic impurities such as resin and oil. Chemical reactivity is kept low. When a highly chemically reactive pre-vinyl alcohol or acrylamide film is formed on this surface as a base layer,
It is presumed that the flame retardant coating agent containing the condensation resin reacts directly and completely with the wood base material and exhibits a high degree of flame retardancy.

(3) Agents used in flame-retardant coating agents The flame-retardant coating agents used in the present invention are made by mixing a water-soluble or water-dispersible condensation resin with a specific cinnamic compound in the form of an aqueous solution or fine powder. It is something.

[Condensation resin]

The condensation resin herein means a methylolated product of urea or/and melamine, and/or an etherified product of these methylolated products with an alcohol having 3 or less carbon atoms. From the point of view of water resistance, it is suitable to use methylolated melamine with a degree of methylolation of 4 or higher, rather than urea resin, but the heat insulating layer formed when heated is hard and brittle when using urea resin. of urea and melamine,
For example, if a co-condensate with an equal weight of formaldehyde or a partially methyl etherified product thereof is used, satisfactory performance can be obtained in terms of water resistance and moisture resistance. Examples of typical condensation resins suitable for use in the present invention are shown in Table 1. However, the viscosity is measured using a B-type viscometer at 20° C., and a high viscosity indicates that the molecular weight has increased to some extent due to methylene condensation. Also, r time is 1
00? 511 Ll of 10% ammonium chloride to the product
In addition, it is the time taken until fluidity is lost when stirred with a stirrer at a predetermined temperature.

[Sin compounds]

Next, the compound mentioned here is the following compound.

b) EXOLI, which is commercially available as a fine powder of ammonium polysinate (for example, from Hoechst Japan Co., Ltd.)
T 422) A fine powder of ammonium polysinate microencapsulated with melamine resin (for example, 0LIT 46, commercially available from Hoechst Jano 4 Co., Ltd.)
2) C) A fine powder of ammonium polysinate microencapsulated with resin (for example, EXOLIT 4 commercially available from Hechu Stoja 97 Co., Ltd.)
55) (Note) A) 2 mouths), C) Tomoshin content is approximately 29.0±
1.0%, with a nitrogen content of about 13-. stomach)
is ammonium polysinate with a molecular weight of 70,000 to 70,000 - SO, OOO, which is used as a matrix and microencapsulated with a synthetic resin thin film.
In both cases, the amount of water-soluble salts in both cases was significantly reduced. Since formaldehyde liberated from the condensation resin blended in the flame retardant formulation reacts with the ammonia group of ammonium polysinate, it is preferable to use (a) and (c) in the present invention.

2) 3-(Dialkylphosphono)propionamide (however, the alkyl group has 3 or less carbon atoms) and their reaction products with formaldehyde, i.e. their monomethylolated products, dimethylolated products, bis-(β-3-( (dialkylphosphono)-propionamide) and its N-methylolated product. Among these, 3-(dimethylphosphono)propionamide has the best fire protection and water resistance, and is used in the form of an aqueous solution. All methylol compounds tend to have low reactivity with the above-mentioned condensation resin. The 3-(dimethylphosphono)propionamide has a syn content of 17.1% and a nitrogen content of 7.7 ts.

In addition, the above-mentioned A) 2) and C) both have a sink content of 29.0±1%, and when used in combination with the above-mentioned condensation resin, they become excellent flame-retardant coating agents for wood.

In particular, microencapsulation using synthetic resins significantly reduces water solubility and reactivity with formaldehyde, which is released from condensed resins, giving excellent performance. Since they are water-insoluble fine particles, they are not suitable for making the polyvinyl alcohol or polyacrylamide layer of the base coating agent flame retardant or for imparting the ability to form a foamed heat insulating layer to this layer. However, the above 2) 3-(dialkylphosphono)propionamide has excellent permeability because it is water-wettable, and in the coexistence of the above-mentioned condensed synthetic resins, it cannot be used in layers of polyvinyl alcohol or polyacrylamide or the like. It chemically bonds with the wood part of the lower layer, giving it an excellent ability to form a foamed heat insulating layer, and also contributes to preventing cracking by plasticizing the condensation resin.・) The amount that can be cured by the condensation resin is very low, and the amount that can be cured by the condensation resin is very low, and the amount that can be cured by the condensation resin is about half of that of the condensation resin in terms of solid content, so this alone has no flame retardant effect. b) 2 mouths)
It has the disadvantage that it is slightly lower than (c) and (c). Therefore, in the case of 2), by using one type or two or more of 1) or 3), it will completely penetrate into the surface treatment agent film and have very good fire prevention performance as a whole. A flame retardant formulation can be obtained.

[Formulation of flame retardant paint]

As for the formulation of the flame retardant coating agent used in the present invention, there are many possible formulations using the compounds shown above, but the following mixture of flame release agents (-!!-st) is the most fire-resistant. This is an example of excellent performance, and it is convenient to make a two-part formulation of this and a condensation resin.

B) Examples of flame retardant mixtures Table 2 (Note) Contains 21.3% nitrogen valve 11.
3% solid content 86.2% volatile content 13.2
% of water) Example of flame retardant coating formulation and curing conditions Table 3 [Other additives] To obtain a coating film without air bubbles, it is desirable to use an antifoaming agent, and commercially available silicone-based or oil-based Antifoaming agents, octyl alcohol, etc. can be used. It is preferable to use an emulsified dispersion of K to prevent sedimentation of microencapsulated ammonium polysinate fine powder, and various surfactants can be used for this purpose, but non-ionic surfactants such as nonylphenol with ethylene oxide can be used. The use of the agent is preferable because it does not reduce the flame retardant performance.

As shown above, if you add ammonium chloride, ammonium sulfupate, diammonium phosphate, etc., which are curing catalysts for condensation resins, to the flame retardant mixture in advance, you can create a two-part type that can be used in combination with condensation resins. You can get a prescription. If you want to cure at room temperature and obtain water resistance, use the recipe (1) in Table 3. , p-) It is necessary to add a small amount of a strong acid, such as luenesulfonic acid, sulfamic acid or sulfuric acid.

(Example) Hereinafter, the present invention will be further explained using examples.

[Examples 1 to 3] and [Reference Examples 1 to 3] Type of 5-f lie with a thickness of 9 mm ■ Apply base coating to plywood according to the recipe in Table 4 using a brush, and apply at 65°C. Dry until the temperature is constant, then apply the flame retardant coating agent shown in Table 2 as shown in Table 4,
After curing at 45℃ for 10 days until the temperature becomes constant, JIS
A heating test for flame retardant class 3 of A-1321 was conducted. The results are shown in Table 4. The meanings of the abbreviations are as described in 4. above. Indicated in (Note) of (2) A). Note that the heating test results are the average value of three measurement data.

[Examples 4 to 6] and [Reference Example 4] 3-Tie 11 plywood with a thickness of 5.5 Ill111 was coated with 8077 m'' (as an aqueous solution) using a roll coater using the base coating recipe as shown in the table below. 1 at 80℃
Dry for 5 minutes. In Example 5, the methylated product of 70% hexamethylolmelamine and ammonium chloride were used for the purpose of improving water resistance and drying speed by chemically crosslinking. In addition, by adding lydium chloride, this highly deliquescent property is used to prevent excessive drying of the base paint film and the wood parts to which this paint film is applied, and prevent cracking of the flame retardant paint film. This is to do so. Next, a flame retardant coating agent having the formulation shown in Table 3 (2) was applied as a solid component on the base coated layer of 2007.
7m" (approximately 26277m" as a solution) was coated with a flow coater, dried at 80°C for 7 minutes, and when each was semi-dry, the base treatment agent of Example 4 was applied to the back side at a ratio of 5077m2 except for Reference Example 4. After painting and drying oak plywood boards with a thickness of 0.3 m and joining them together, apply light pressure to the entire surface, stack many sheets, press 11 at low temperature, leave for 24 hours, and then apply further pressure. After removing 12077 m of the flame retardant coating agent from Table 3 (2) on the surface of the refinished veneer boards, apply a solution of the flame retardant coating agent shown in Table 3 (2) to the surface of each refinished veneer board at 80°C for 10 minutes.
Heat treatment was performed at 80° C. for 5 minutes.

JIS A1321 of these plywood boards with attached boards
Table 5 shows the results of the flame retardant class 3 heating test for O. is a failure value of 111) Each test item TC: Time during which the exhaust temperature during heating exceeds the standard temperature (50°C added to the exhaust temperature when heating an asbestos pearlite board) (pass condition: 3 minutes or more) Tdθ: Area given by the temperature and time during which the exhaust temperature curve exceeds the standard temperature (passing condition: 350 or less) Cmu: smoke generation coefficient (passing condition: 120 or less) Afterflame: 30 seconds or less (passing) Cracks: All No cracks of 1/10 or less of the thickness should occur (pass) Deformation: Deformation that is detrimental to fire prevention should occur Table 5 [Example 7] and [Reference Example 5] 5 or more joints with a thickness of 121111+ Example 4 was applied to one side of the cypress board of 22αX22cIIL appearing on the surface.
The same base coating agent was applied as a solution at a rate of 7,077 m2, and after drying at room temperature for 2 days, the flame retardant paint formulation from Table 4 (1) was applied as a solution at a rate of 25,077 m2, and dried at room temperature for 7 days. The following differences were found when comparing the cured product (Example 7) and the product that was similarly flame-retardantly coated without surface treatment (Reference Example 5).

Example 7 Reference Example 5 (o) Occurrence of cracks due to outdoor exposure for 3 months None
Ash (c) JISA1321 3rd grade combustion test T 3rd grade combustion test Tc (minute 1 second) 6 minutes or more 4'
05"c person 17.7 46.3 Afterflame 〇 2

Claims (1)

[Scope of Claims] 1. An aqueous solution containing polyvinyl alcohol and/or polyacrylamide as an essential component is applied as a base coating agent to a wood base material, and then a water-soluble or water-dispersible condensation resin is applied as an essential component thereon. A flame-retardant wood material coated with a flame-retardant coating agent. 2. The flame-retardant wood material of claim 1 and the decorative paper or wood veneer coated with an aqueous solution containing polyvinyl alcohol and/or polyacrylamide as an essential component as a base coating agent. A flame-retardant wood material made by bonding a surface coated with a flame-retardant paint and a surface coated with the aqueous solution of the decorative paper or wood veneer. 3. The flame-retardant wood material according to claims 1 and 2, characterized in that the base coating agent is an aqueous solution containing polyvinyl alcohol and/or polyacrylamide in combination with melamine resin as an essential component. .