JPS5838560B2 - Senibanseizo Youketsugozai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a binder for producing fiberboards, and more particularly to a binder for producing fiberboards containing a thermosetting acrylic resin having an epoxy group as an active ingredient.

Mineral fibers such as rock wool, asbestos, and glass wool have been used as reinforcing and protective materials for various structures due to their excellent heat-retaining properties, and especially in recent years, have been used for their fire resistance, heat insulation, sound absorption, and cosmetic properties. It has a wide range of uses as ceiling and wall materials in buildings.

Conventionally, wet methods such as a paste process and a wet felting process have been known as methods for manufacturing mineral fiber boards. Among these, when using the wet felting process, a binder, filler, etc. are usually added to an aqueous slurry of fibers. A method is adopted in which a water repellent, a fixing aid, etc. are added and mixed, water is dehydrated on a wire, the bottom is formed into a plate shape by pressing, the water is dehydrated at the same time, and then the material is dried and finished.

Various conditions are required for the binder used in this case, and these conditions are mainly that the binding effect is excellent, the dry and wet bending strength of the fiberboard is strong, and the properties of the fiberboard as an inorganic material are particularly high. It does not impair fire resistance and heat resistance, it does not reduce the water resistance and moisture resistance of the fiberboard, it prevents the fiberboard from sagging due to moisture absorption (hereinafter referred to as sag resistance), and it causes large flocs when added to fiber slurry. For example, it should not become too much and have a negative impact on workability during fiberboard production.

By the way, starch has conventionally been mainly used as a binder for manufacturing mineral fiberboards by a wet felting process, which is one of the wet methods.

However, starch cannot fully satisfy the above conditions.

In other words, starch has a weak binding force, so in order to maintain the desired strength of the product, it is necessary to add 10 to 20
It is necessary to add as much as % by weight, which naturally lowers the fire resistance of the product, and also makes the water repellency, ie, workability, extremely poor during product manufacture.

In addition, starch itself has extremely low water resistance, so if the fiberboard is used in a high humidity environment such as a kitchen ceiling after installation, the ceiling will absorb moisture and become soft, causing the ceiling to sag, and the starch to rot. This causes mold,
It has the disadvantage that it is difficult to obtain fiberboard of excellent quality.

However, since starch is inexpensive, it is used in large quantities to provide fiberboard with practical strength, and despite the drawbacks mentioned above, starch is still used.

As a result of repeated research aimed at eliminating the various drawbacks of the above-mentioned starch and providing a binder that can replace it, the applicant has found that salts of terpolymer of acrylic acid, acrylamide and acrylonitrile have been found in light. It has been found that the above-mentioned purpose is met.

As a result of further research, a resin obtained by modifying the above terpolymer with epoxy, or a resin emulsion obtained by emulsion polymerizing the epoxy-modified product with a hydrophobic vinyl monomer using it as a protective colloid, was found to be suitable for fiberboard. When used as a manufacturing binder, it far exceeds the bending strength of fiberboard due to starch, and can also provide even better water absorption resistance and sag resistance than the above-mentioned terpolymer resins. After discovering that it can be used as a practical tool, the present invention was completed.

That is, the present invention provides: (1) at least one selected from acrylic acid, methacrylic acid, and crotonic acid (hereinafter referred to as component A); (2) at least one selected from acrylamide, methacrylamide, and crotoamide (hereinafter referred to as component M); An epoxy-modified copolymer obtained by copolymerizing a small amount of acrylonitrile, methacrylonitrile, and crotonitrile (hereinafter referred to as N component), and an alkali metal salt or ammonium salt of the modified product as an active ingredient. A binder for manufacturing fiberboard characterized by containing ■A
Acid component (1) A copoxy modified product of a copolymer obtained by copolymerizing the M acid component and (2) N component, and 100 parts by weight or less (
A resin emulsion obtained by emulsion polymerization of one or more hydrophobic vinyl monomers (preferably 5 to 30 parts by weight), or a copolymer obtained by copolymerizing the above (1), (2) and (2), or the copolymer. Alkali metal salt or ammonium salt of 10
Containing as an active ingredient a resin emulsion obtained by emulsion polymerizing 100 parts by weight or less of one or more hydrophobic vinyl monomers in the presence of 0 parts by weight, followed by reaction with shrimp halohydrin and epoxy modification. The present invention relates to a characteristic binder for manufacturing fiberboard.

Epoxy-modified copolymers of the above-mentioned compounds (1), (2) and (2) used as binders in the present invention can be prepared by well-known methods.

For example, a ternary copolymer obtained by copolymerizing the A component, M component, and N component in advance by a conventional method, or by hydrolyzing a copolymer of the M component and the N component and using a part of the copolymer as the A component. Coalescence with an alkali at pH 7 or below, preferably pH 5-6
An epoxy-modified product can be obtained by adjusting the epoxy resin and reacting it with epihalohydrin such as epichlorohydrin.

Furthermore, an epoxy modified product can be obtained by copolymerizing component A, component M, and component N in the presence of one or more epoxy monomers such as glycidyl acrylate, glycidyl methacrylate, and vinyl glycidyl ether. .

In general, it is preferable to carry out the former method in order to obtain this epoxy modified product, and according to this method, the viscosity can be easily adjusted during the polymerization process.

Further, the alkali salt of the above-mentioned epoxy modified product can be easily prepared by, for example, reacting it with an alkali such as an alkali metal hydroxide or ammonia according to a conventional method.

In the present invention, the amount of each monomer used to obtain the epoxy modified product can vary within a wide range, but usually 5 to 2 % of component A is used.
0 mol%, M component 35-75 mol% and N component 20
The amount of the epoxy compound added is preferably 2 to 1% by mole based on the total amount of A, M, and N components.
The content is preferably 7 mol%.

The copolymerization reaction of the A, M and N components may be carried out by any means commonly used for polymerization of acrylic monomers.

For example, polymerization is carried out by dispersing or dissolving the monomer in a suitable solvent and heating it in the presence of a polymerization initiator.

In the present invention, it is particularly desirable to use water as a medium, thereby obtaining an aqueous dispersion of the copolymer.

The degree of polymerization of the above copolymer can be appropriately adjusted by adding a chain transfer agent such as allyl alcohol or isopropyl alcohol during polymerization.

Further, when the above copolymerization reaction is carried out in the presence of an epoxy monomer, the proportions of the A, M and N components may be adjusted as appropriate in consideration of the amount of the epoxy monomer used.

This epoxy modification is necessary to impart thermosetting properties to the copolymer, and the epoxy modified copolymer obtained as described above has excellent properties as a binder for fiberboard production due to its large cohesive strength. demonstrate.

In addition, the concentration of this epoxy modified product is usually 10 to 20% by weight.
It is obtained in the form of an aqueous dispersion of.

The epoxy-modified copolymer of the present invention and its alkali metal salt or ammonium salt can be used alone or in combination with starch as a binder.

When the epoxy-modified copolymer is used alone, for example, only 2 to 6% by weight of the mineral fiber is added.
It exceeds the bending strength of fiberboard made from conventional starch, and also exhibits remarkable effects in terms of water absorption and sag resistance.

Furthermore, since the epoxy modified product of the present invention is used in a very small amount compared to starch, the resulting fiberboard has excellent fire resistance, and even when the fiberboard is heated, its calorific value is extremely small.

When using the epoxy modified copolymer of the present invention, it may be added in the same manner as conventional starch, and no special operations are required.

- For example, a product can be manufactured by adding an epoxy-modified substance to an aqueous slurry of mineral fibers and using aluminum sulfate or other known acidic fixing aids or cationic fixing aids to improve fixation. Furthermore, moisture proofing agents such as wax-based, rosin-based, or petroleum resin-based sizing agents, and fillers such as clay, Merck, and asbestos may be added in combination.

If the epoxy-modified copolymer of the present invention or its salts are used in combination with starch as a binder, the two will undergo a crosslinking reaction during heating and drying of the product, exhibiting a strong binding effect with excellent water resistance.

Therefore, the epoxy modified product acts as a starch waterproofing agent, but according to the experiments of the present inventors, urea-formaldehyde resin, which has been known as a starch waterproofing agent in the membrane paper industry, The use of ketone-formaldehyde resins as binders in the present invention has been found to be extremely ineffective.

This is probably due to the fact that the epoxy modified product produced according to the present invention has fixing ability for mineral fibers and binding strength between fibers.

The present invention also provides a binder which does not impair the performance of the above-mentioned epoxy modified products and their alkali salts as a binder, and whose cohesive force is suppressed to some extent.

That is, the present invention also uses a resin emulsion obtained by emulsion polymerization of a hydrophobic vinyl monomer using the above-mentioned epoxy modified product as a protective colloid as a binder.

According to this resin emulsion, when it is used as a binder, there is no fear of forming flocs in the fiber slurry even when used in a relatively large amount, and it exhibits a binding effect similar to that of epoxy-modified products, resulting in a uniform board at all times. It becomes possible to manufacture fiberboards of

The resin emulsion in the present invention uses an epoxy-modified copolymer as a protective colloid, and one or more hydrophobic vinyl monomers are added to the protective colloid so that the solid content of the protective colloid is 1.
It can be easily obtained by adding it in an amount of 100 parts by weight or less, preferably 5 to 30 parts by weight, based on the weight of 0.00 kg and carrying out emulsion polymerization.

The emulsion polymerization may be carried out by a generally well-known method.

For example, a hydrophobic vinyl monomer is added to an aqueous dispersion of the above-mentioned epoxy-modified product and subjected to emulsion polymerization using a radical initiator such as potassium persulfate, or a hydrophobic vinyl monomer is added to an aqueous dispersion of a copolymer of A, M, and N components. After adding monomers and carrying out emulsion polymerization using a radical initiator, the copolymer may be further reacted with epihalohydrin to modify the copolymer with epoxy.

Generally, it is preferable to employ the latter method because it allows easy viscosity adjustment.

The emulsion resin obtained in the above manner can be used as a binder for manufacturing fiberboards as it is or as an alkali salt in accordance with a conventional method, similar to the epoxy-modified copolymer of the present invention, and has excellent effects. demonstrate.

Hydrophobic vinyl monomers used in the above include vinyl acetate, vinyl propionate, acrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate,
Examples include 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and styrene.

Further, it is preferable that the proportion of the dihydrophobic monomer used in the epoxy-modified copolymer is equal to or less than the same weight; if it is used in excess of the same weight, the performance as a binder, particularly the binding effect, will deteriorate.

The binder of the present invention is applicable not only to the production of mineral fiberboards, but also to soft fiberboards made from wood pulp.

When pulp is used as a raw material for soft fiberboard, by using about 1 to 3% by weight of the binder of the present invention to the pulp, it exhibits a strong binding effect with excellent water resistance.
Excellent quality fiberboard is obtained.

Examples will be given below to explain the present invention in more detail.

Example 1 20M' of deionized water was charged into a 2L five Rokolben equipped with a thermometer, a stirrer, a nitrogen gas inlet tube, and two dropping funnels, and the temperature was raised to 78°C while stirring.

Next, acrylamide 240f, acrylonitrile 119
．． 4S' and acrylic acid (80 wt% aqueous solution) 50.1
'(molar ratio 60:40:lO) with deionized water 1185S
From one dropping funnel, also add persulfate IJ40s with 8.02ml of allyl alcohol and 100ml of deionized water.
were simultaneously added dropwise from the other dropping funnel, and the reaction vessel was maintained at 78°C.

The above monomer solution and catalyst solution were uniformly dropped over a period of 3 hours.

Next, the temperature of the reaction vessel was raised to 85° C. and maintained at this temperature for 30 minutes to complete the reaction.

After cooling the mixture to below 70°C, 11:1 l of caustic soda was dissolved in 10 l of tap water and added to obtain a ternary copolymer with a concentration of 20.9%, a viscosity of 660 cps (at 25°C), and a pH of 5.5. A combined aqueous dispersion was obtained.

An aqueous dispersion of this terpolymer is used as comparative binder A.

Next, 500 tons of the aqueous dispersion of the terpolymer obtained above was charged into a 1-ton four-piece Locolben equipped with a thermometer, stirrer, and dropping funnel, and 5.0 tons of epichlorohydrin was added thereto.
81 and 183 tons of tap water were added and reacted at 60°C for 3 hours to obtain a yellow transparent aqueous solution with a concentration of 15.4%, a viscosity of 150 cps (at 25°C), and a pH of 5.0.

This aqueous solution of the epoxy-modified acrylic terpolymer is referred to as the binder 1 of the present invention.

Example 2 The aqueous dispersion of acrylic terpolymer 3001 obtained in the first half of Example 1 was charged into a 1-ton five-piece Lokolben equipped with a thermometer, stirrer, nitrogen inlet tube, and two dropping funnels. 6
The temperature was raised to 5-70°C, and 3.5'i? of vinyl acetate was added from one dropping funnel while stirring. and acrylonitrile 3.51? C
Acrylic copolymer: vinyl acetate + acrylonitrile
9:1 (solid weight ratio)], and 0 and 35 f potassium persulfate solution dissolved in deionized water were simultaneously added dropwise from the other dropping funnel, each taking 30 minutes.

After the completion of the dropwise addition, the reaction was carried out at 65 to 70°C for 30 minutes, and then a solution of 0,35P potassium persulfate dissolved in deionized water was added, and the reaction was carried out at 75 to 80°C for 1 hour to complete the polymerization reaction.

Tap water Ion was added to this, the temperature was adjusted to 60°C, 3.51% of epichlorohydrin was added and reacted for 3 hours, and the concentration was 1.
4.4%, viscosity 205 cps (25°C) and pH 4
, 7 was obtained.

This resin emulsion is referred to as the binder 2 of the present invention.

In the above, the amount of vinyl acetate and acrylonitrile used was 70 g each [acrylic copolymer: vinyl acetate + acrylonitrile = 3 nia (solid content weight ratio)], and the following procedure was similarly obtained, with a concentration of 14.7 and a viscosity of 20. cps (2
Comparative binder B is a milky white emulsion at pH 5.2).

Example 3 One ounce of the epoxy modified product obtained in Example 1 was charged into a five-piece Locolben equipped with a thermometer, a stirrer, a nitrogen gas inlet tube, and two dropping funnels, and the temperature was raised to 65 to 70°C with stirring.

Next, add 0.91f of vinyl acetate and 0.9f of acrylonitrile from one dropping funnel. [Epoxy-modified acrylic terpolymer: A 9:1 (solid weight ratio) mixture of vinyl acetate and acrylonitrile was dissolved in 5 z of deionized water from the other dropping funnel, and a solution of 0.0 and 1 oz. of potassium persulfate was added. 30 each
It took several minutes to drip them all at the same time.

After the dropwise addition was completed, the reaction was carried out at 65 to 70°C for 30 minutes, and then a 0.1S' potassium persulfate solution dissolved in 5 g of deionized water was added, and the reaction was carried out at 75 to 80°C for 1 hour to complete the polymerization reaction. .

This resulted in a concentration of 15.1% and a viscosity of 315 cps (2
A milky white emulsion with a pH of 4.6 was obtained.

This resin emulsion is referred to as the binder 3 of the present invention.

Example 4 According to the method of Example 1, acrylamide 178i, methacrylamide 85z1, acrylonitrile 781, and methacrylic acid 431 (molar ratio 50:20:30:10) were polymerized in aqueous solution, and after the reaction, neutralized with an aqueous solution of caustic soda to pH 5.5. An aqueous solution of was obtained.

This was then carried out in Example 1 using epichlorohydrin 23i.
Modified with epoxy in the same way as , concentration 15.6%, viscosity 14
A clear yellow aqueous solution of 3 cps (25° C.) and pH 4.9 was obtained.

The obtained aqueous solution of the epoxy-modified acrylic copolymer is referred to as the binder 4 of the present invention.

Example 5 According to the method of Example 1, 250 g of acrylamide, 53 g of acrylonitrile, 431 g of methacrylonitrile and 4:11 crotonic acid (molar ratio 70:20:10:10)
was polymerized in an aqueous solution, and after the reaction, it was neutralized with an aqueous solution of caustic soda to obtain an aqueous solution with a pH of 5.4.

Then, Example 1 was prepared using 20 g of epichlorohydrin.
Modified with epoxy in the same way as , concentration 15.8%, viscosity 16
A yellow clear aqueous solution of 2 cps (25° C.) and pH 5.0 was obtained.

The obtained aqueous solution of the epoxy-modified acrylic copolymer is referred to as the binder 5 of the present invention.

※※ Rock wool boards were manufactured using the binders 1 to 5 of the present invention and comparative binders A-B obtained above, either alone or in combination with cornstarch (cooked), and the performance of the resulting products was tested. .

That is, rock wool was uniformly suspended in water, and 6% by weight of clay based on the solid content of rock wool was added to this slurry, and the mixture was thoroughly stirred. % (if used in combination with starch, each binder 2
After adding 2% by weight of starch, 2% by weight of sulfuric acid based on the solid content of rock wool was added and mixed uniformly.

The mixed slurry was filtered through a 16-mesh wire gauze, and the resulting cake was cold pressed at a pressure of 1 kg/ctrl for 30 seconds and then dried with hot air at 150° C. for 3 hours.

A plate having a thickness of 12, O±0.3 and a specific gravity of 0.38±0.01 was left in a constant temperature and humidity chamber for one day and night, and then tested according to the following test method.

The results are shown in Table 1 below. In Table 1, cornstarch alone is used as a comparative binder C at 12% by weight based on solid content of rock wool.
The results of a similar test on the rock wool board obtained using this method are also listed.

〔Test method〕

(1) Bending strength; JIS A-5905 (197
0).

(2) Water absorption: Measured according to JIS A-5905 (1970) for fiberboards immersed in water for 2 hours.

(3) Fire resistance test: Base material test Nikki JIS A132
1 (1970).

(4) Sag resistance: Place a test piece with a width of 1 inch and a length of 1.02 feet on a metal frame with a span width of
The specimen was left in a constant temperature and humidity environment of 90% RH until the moisture content became constant (usually about 4 days), and the distance by which the center of the specimen flexed was measured in units of distance.

Therefore, the smaller the value, the better.

Wood fiberboards were then produced using Binders 1 and 2 of the present invention and Comparative Binder A, either alone or in combination with gelatinized corn starch, and the performance of the resulting products was tested.

That is, the wood fibers are uniformly suspended in water, and each binder is added at 3% by weight based on the wood fibers (if used in combination with starch, 1% by weight of each binder and 3% by weight of starch) with stirring. A sulfuric acid band was added in an amount of 2.5% by weight based on wood fibers and mixed uniformly.

This mixed slurry 0 was filtered through a 16-mesh wire gauze, and the resulting cake was cold-pressed at a pressure of 2.0 kg/cr;t for 2 minutes, transferred to a dry air dryer, and heated and dried at 150° C. for 3 hours.

Plate thickness 1.05±0.3 mm, specific gravity 0.27±0.01
After being left in a constant temperature room for one day and night, it was tested according to the above test method.

The results are shown in Table 2 below. In Table 2, gelatinized corn starch is used as a conventional binder, and the solid content of this solution is 4.0% by weight (as binder) and 6% by weight (as binder E), respectively. ) was added to produce wood fiberboard, and its performance was tested in the same manner as above.The results are also listed.

Example 6 1 of the epoxy modified product obtained in Example 1 was placed in a four-piece locolben equipped with a thermometer, a stirrer, a nitrogen gas inlet tube, and a dropping funnel.
00? The mixture was stirred and heated to 45-50'C.

Next, 1.01% 10% hydrogen peroxide solution and 0.3% sodium tartrate. into the above-mentioned Kolben, and then add 0.9S' of vinyl acetate and 0.9S' of acrylonitrile from the dropping funnel.
A mixture of f (epoxy-modified acrylic terpolymer: (vinyl acetate + acrylonitrile) -9:1 (solid weight ratio)) was added dropwise over 30 minutes.

After the dropwise addition was completed, the reaction was carried out at 45 to 50°C for 30 minutes, and then 10% hydrogen peroxide solution was added.4. Off and 0.3 f of sodium tartrate were added and reacted at 45-50°C for 1 hour.

This resulted in a concentration of 15.3% and a viscosity of 403 cps (2
A milky white emulsion of 5°C) and pI (5,2) was obtained.

This will be referred to as binder 6.

A rock wool fiberboard was manufactured in the same manner as in Example 5 using the binder 6 described above.

The performance test results of the obtained rock wool fiberboard are shown below.

Example 7 Same as Example 2 except that vinyl acetate was 3.51 and methyl acrylate was 3.51, concentration was 14.8%, viscosity was 2.
Milky white at 50 cps (25°C) and pH 4.8**
I got an emulsion.

This emulsion is used as a binder 7.

A rock wool fiberboard was produced in the same manner as in Example 5 using the binder 7 described above.

The performance test results are shown below. Comparative Example 1 Aqueous copolymer solution of acrylamide and sodium acrylate (
Epichlorohydrin (concentration 15%, viscosity 8000 cps, molar ratio of acrylamide and sodium acrylate 92:8) was added in an amount of 0.2 mol per 1 mol of amide group, and the mixture was reacted at 70 to 75°C for 90 minutes. Viscosity 5600
An aqueous solution of epoxy modified product of cps (25°C) was obtained.

This epoxy modified aqueous solution is used as a comparative binder.

Comparative example 2 Vinyl acetate 81.8f, ethyl acrylate 4.3P.

1.7% of glycidyl methacrylate and 0.71% of maleic anhydride were added to the base (I) of JP-A-48-11403.
Emulsion polymerization was carried out according to the description (p. 7-8), and the concentration was 30%.
, a milky white emulsion with a viscosity of 35 cps (25°C) was obtained.

This is designated as Comparative Binder E. Comparative Example 3 Io% aqueous solution of polyamide polyamine epichlorohydrin resin (synthesized from adipic acid, diethylenetriamine and epichlorohydrin) (viscosity 50 cps (25°C)
)) was obtained, and this was designated as comparative binder F.

Rock wool boards were manufactured using the comparative binders obtained above, either alone or in combination with cornstarch (cooked), and the performance of the resulting products was tested.

The results are shown in Table 4.

Claims (1)

[Scope of Claims] 1 ■ At least one selected from acrylic acid, methacrylic acid, and crotonic acid; ■ At least one selected from acrylamide, methacrylamide, and crotoamide; and ■ Selected from acrylonitrile, methacrylonitrile, and crotonitrile. A binder for producing fiberboards, characterized by containing as an active ingredient an epoxy-modified product of a copolymer obtained by copolymerizing a small amount of 2. At least one selected from acrylic acid, methacrylic acid and crotonic acid; ■ At least one selected from acrylamide, methacrylamide and crotoamide; and ■ At least one selected from acrylonitrile, methacrylonitrile and crotonitrile. Emulsion polymerization of 100 parts by weight or less of one or more hydrophobic vinyl monomers in the presence of 100 parts by weight of an epoxy modified product of the copolymerized copolymer or an alkali metal salt or ammonium salt of the modified product. 100 parts by weight or less of a hydrophobic vinyl monomer in the presence of 100 parts by weight of a resin emulsion obtained by copolymerizing the above (1), (2) and (2), or an alkali metal salt or ammonium salt of the copolymer. 1. A binder for producing a fiberboard, comprising as an active ingredient a resin emulsion obtained by emulsion polymerization of one or more of the following, followed by reaction with epihalohydrin and epoxy modification.