JPS641587B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION This invention relates to fiber binders. More specifically, the amount of ethylenically unsaturated monocarboxylic acid (hereinafter referred to as ethylenically unsaturated carboxylic acid) or ethylenically unsaturated polycarboxylic acid is 0.1 to 0.1 to 100 parts of resin.
An aqueous ethylene-vinyl acetate copolymer dispersion (A) with an ethylene content of 8 to 30% by weight and a vinyl acetate content of 92 to 70% by weight, which is obtained by copolymerizing 3.0 parts, has two or more aziridine groups in the molecule. Aqueous dispersion of compound (B)
The ratio of the amount of aziridine groups in the aqueous dispersion (B) of a compound having two or more aziridine groups in the molecule to the amount of carboxylic acid in the aqueous copolymer dispersion (A). However, aziridine group/carboxylic acid = 0.3 mol to 10 mol/
It relates to a fiber binder characterized in that it is 1 mol. Traditionally, water-based fiber binders include SBR,
NBR latex, acrylic emulsion, vinyl chloride emulsion, and vinyl acetate emulsion are used, but most binders are applicable to a wide range of textile materials and have excellent adhesive properties, water resistance, and oil resistance. do not have. The present invention provides natural fibers,
In order to develop an adhesive that easily adheres to cellulose-based semi-synthetic fibers, polyester, nylon, acrylic, and other synthetic fibers, we focused on an aqueous ethylene-vinyl acetate copolymer dispersion and attempted to improve its water resistance and oil resistance. As a result, we have discovered a fiber binder that is significantly improved compared to conventional ethylene-vinyl acetate aqueous dispersions. That is, the present invention introduces a carboxyl group into an ethylene-vinyl acetate copolymer and uses as a crosslinking agent an aqueous dispersion having two or more aziridine groups that easily react with the carboxyl group, thereby achieving a long pot life and crosslinking. It has been found that the effect is extremely large, resulting in a fiber binder with greatly improved water resistance and oil resistance. Combinations of carboxyl groups and diepoxy groups, hydroxyl groups or amide groups and isocyanates are known as methods for crosslinking with bifunctional groups by introducing active hydrogen into an aqueous ethylene/vinyl acetate copolymer dispersion, but the pot life is short. Therefore, there are many problems. JP-A-53, which has a long pot life and is considered to be practical.
-33251, an aqueous ethylene-vinyl acetate copolymer dispersion with a functional group containing active hydrogen, and a combined system with a catalyst that promotes the dissociation of blocked isocyanates are also considered, but these methods extend the pot life, but do not reduce the isocyanate. Systems that dissociate and react cannot provide sufficient water and oil resistance. That is, water resistance and oil resistance are improved by making an aqueous dispersion of ethylene-vinyl acetate copolymer into which a carboxylic acid group has been introduced and using in combination an isocyanate blocked with an aliphatic alcohol, an aromatic alcohol, an oxime, etc., and a dissociation and reaction catalyst. However, the ethylenically unsaturated monocarboxylic acid or ethylenically unsaturated polycarboxylic acid of the present invention may be used with ethylene/vinyl acetate having an ethylene content of 8 to 30% by weight and a vinyl acetate content of 92 to 70% by weight. An aqueous dispersion (B) of a compound having two or more aziridine groups in the molecule is added to an aqueous dispersion (A) of a copolymer copolymerized in an amount of 0.1 to 3.0 parts by weight based on 100 parts by weight of the polymer. The copolymer aqueous dispersion (A)
The ratio of the amount of aziridine groups in the aqueous dispersion (B) of the compound having two or more aziridine groups in the molecule to the amount of carboxylic acid in the molecule is aziridine group/carboxylic acid = 0.3 mol to 10 mol/
Much better performance is shown when the fibers are bonded with a fiber binder characterized by 1 molar. Further, the effect is small in a composition of an aziridine group and an aqueous ethylene-vinyl acetate copolymer dispersion containing an active hydrogen other than a carboxyl group as a functional group. It is presumed that this is not simply due to the reactivity between the aziridine group and the carboxylic acid group, but the mechanism is not clear. In the present invention, the reason for the long pot life, stability, and high curing efficiency is that the ethylene-vinyl acetate copolymer aqueous dispersion is mixed with a curing agent for the aqueous dispersion. It is believed that the synergistic effect of the combined aqueous dispersion and the aqueous dispersion containing an aziridine group is the reason for the significant improvement in water resistance and oil resistance. The ethylene-vinyl acetate copolymer aqueous dispersion (A) used in the present invention contains 0.1 to 3.0 parts of ethylenically unsaturated carboxylic acid or ethylenically unsaturated polycarboxylic acid per 100 parts of resin. However, the copolymer is emulsion copolymerized under pressure with ethylene so that the ethylene content is 8 to 30% by weight and the vinyl acetate content is 92 to 70% by weight. If the ethylene content is less than 8% by weight, the fat will be too hard and will lose its flexibility, and the water resistance will drop significantly, making it impossible to achieve the improvement in water resistance that is the objective of the present application. On the other hand, if it exceeds 30% by weight, the reaction pressure will be high and the manufacturing cost will be high, as well as the resin will be soft and its strength will be low and adhesiveness will decrease. Ethylenically unsaturated carboxylic acids to be copolymerized into the ethylene-vinyl acetate copolymer include acrylic acid, methacrylic acid, crotonic acid, etc., and ethylenically unsaturated polycarboxylic acids include maleic acid, fumaric acid, itaconic acid, etc. included. These carboxylic acid compounds are polymerized as carboxylic acids or carboxylic acid salts, but are effective in either state. The protective colloid or surfactant used in producing the ethylene-vinyl acetate copolymer aqueous dispersion is not particularly limited, but a protective colloid is preferable to improve oil resistance, and polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinyl alcohol derivatives, etc. It is desirable to use polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, etc. in combination. The amount of carboxylic acid is 0.1 to 100 parts by weight of resin.
Limited to 3.0 parts by weight. If the amount of carboxylic acid is less than 0.1% by weight, the water resistance and oil resistance will be low;
If it exceeds % by weight, the polymerization rate will drop significantly, and as the amount of catalyst increases, the amount of electrolyte in the dispersion will increase, and the particle size will also increase, resulting in a decrease in storage stability. Furthermore, when such a dispersion having a large particle size is used in combination with a dispersion containing an aziridine group (B), a sufficient effect of improving water resistance cannot be obtained even if heat treatment is performed. In addition, it becomes difficult to use in actual processes due to a decrease in storage stability. As mentioned above, the copolymer aqueous dispersion is a copolymer aqueous dispersion containing vinyl acetate, ethylene, ethylenically unsaturated carboxylic acid, or ethylenically unsaturated polycarboxylic acid as the main components, but the adhesive property is It is also possible to copolymerize with other monomers that are easily copolymerized with vinyl acetate, as long as they are not lost. Examples of such monomers include vinyl formate, vinyl propionate, vinyl butyrate, and vinyl saturated branched fatty acids having an average carbon number of 10 (trade name: Veova10, manufactured by Ciel Chemical).
fatty acid vinyl esters other than vinyl acetate, vinyl chloride, halogenated olefins such as vinyllidene chloride, methyl acrylate, ethyl acrylate,
Acrylic acid esters such as butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, hydroxyethyl acrylate, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate Allyl compounds such as methacrylic esters such as allyl alcohol, allyl glycyl ether, and diallyl phthalate, as well as acrylamide, N-methylolacrylamide, triallyl cyanurate, and vinyl sulfonate can be used. As the aqueous dispersion (B) used in the present invention, a polyaziridine compound having two or more aziridine groups in one molecule is used. For example, ethyleneimine adducts of polyisocyanates, i.e. polycarbamic acid amides of aziridine, more specifically tolylene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, methylene bis(4-
phenyl isocyanate), ethyleneimine adducts of isophorone diisocyanate, etc. In addition, aziridine thiocarbamic acid amide, aziridine phosphoric acid amide, aziridine cyanuric acid amide, etc. can also be used. The aqueous dispersion of the above compound is prepared by a conventionally known method of adding a solvent, water, and an emulsifier to emulsify. As mentioned above, in the crosslinking reaction system of the present invention, the aziridine group in the aqueous dispersion and the carboxylic acid in the aqueous ethylene-vinyl acetate copolymer dispersion are easily mixed and dispersed microscopically to form a film-forming bond. The crosslinking effect increases when the product is heated, and one of the effects of the present invention is that the aqueous curing agent dispersion containing an aziridine group exhibits a remarkable crosslinking effect just by adding a small amount, and improves water resistance and oil resistance. It is. When adding an aziridine group-containing compound dissolved in a solvent, it is possible to mix it relatively microscopically by mechanically stirring it with a large shear force, but it is not practical because it causes foaming in the composition. Even when the compound is added as it is, it is difficult to uniformly micro-mix it. The temperature of the crosslinking reaction using the composition of the present invention is relatively low, and moreover, compared to the crosslinking reaction of blocked isocyanate compounds, the blocking agent is less likely to dissociate and remain, thereby reducing adverse effects on the physical properties of the composition and hygiene. There is no risk of the above problem occurring. The ratio of the ethylene-vinyl acetate copolymer aqueous dispersion (A) to the aqueous dispersion of a compound having two or more aziridine groups in the molecule (B) is the carboxylic acid in the ethylene-vinyl acetate copolymer aqueous dispersion. This corresponds to the number of aziridine groups, but it is necessary that the amount of aziridine groups is 0.3 to 10 moles per 1 mole of carboxylic acid. If it is less than 0.3 moles, the crosslinking effect will be small, and if it is added more than 10 moles, the crosslinking effect will not improve. Thickeners, plasticizers, antifoaming agents, etc. can also be added to the composition. The present invention relates to a fiber binder, and the fiber binder refers to a binder that binds between fibers or a binder that binds fibers and other materials. The former refers to nonwoven fabric binders, binders for flock processing, pulp board binders, carpet binders, binding binders for textile products, etc.; the latter refers to binding of textiles and foam, binding of textiles and PVC sheets or films, and textiles. This refers to the combination of leather, etc. As a method of using the crosslinkable composition of the present invention,
Ethylenically unsaturated monocarboxylic acid or ethylenically unsaturated polycarboxylic acid with an ethylene content of 8 to
30% by weight, based on 100 parts by weight of ethylene-vinyl acetate copolymer with a vinyl acetate content of 92-70% by weight
An aqueous dispersion (B) of a compound having two or more aziridine groups in the molecule is added to an aqueous dispersion (A) of a copolymer copolymerized in an amount of 0.1 to 3.0 parts by weight. With respect to the amount of carboxylic acid in the dispersion (A),
The ratio of the amount of aziridine groups in the aqueous dispersion (B) of the compound having two or more aziridine groups in the molecule is aziridine group/carboxylic acid = 0.3 mol to 10 mol/
A composition of 1 mol is prepared, adjusted to an appropriate viscosity, and then impregnated or coated on a substrate to give a composition of 100 to
A common method is heat treatment at 190°C. In this case, if the heat treatment temperature is 100°C or lower, the crosslinking reaction rate is slow and the treatment time becomes long, and if the heat treatment temperature is 190°C or higher, the base material deteriorates significantly, which is not preferable. The present invention will be explained below with reference to Examples, but these Examples are not intended to limit the present invention in any way. Parts and percentages hereinafter are based on weight unless otherwise specified. Example 1 Using 4 parts of polyvinyl alcohol with an average degree of polymerization of 500 and a degree of saponification of 88 mol% as a protective colloid, 80.5 parts of vinyl acetate, 19 parts of ethylene, and 0.5 parts of acrylic acid were polymerized using ammonium persulfate as a catalyst to obtain a viscosity of 80 cp.
(B type viscometer 60 rpm, same below), solid content concentration 49.0
%, pH 7.0 aqueous dispersion (A) was obtained. An aqueous dispersion ( B) (solid content 25
%) were added and mixed. (The number of moles of aziridine group per mole of carboxylic acid is 1.36 moles.) Water was added to the above composition to make an impregnating liquid with a solid content of 3%, which was used as a binder for a polyester web in the following manner. In other words, polyester web (1.4 denier, 51mm staple, basis weight 16.5g/
^m2 ) cut into 15 x 18 cm (length x width), stacked 6 pieces and sandwiched them together with nylon gauze in a sandwich shape.
After impregnating with the above 3% impregnating solution, take it out and place it on a glass plate, gently rotate it up and down and left and right with a rubber roller (1 kg weight) to squeeze out the core, and then use a mangle to reduce the impregnated amount to 20% (solid). (min)/fiber weight and squeeze the liquid. Then, remove the nylon gauze and dry the sample at 60°C for 30 minutes. The test pieces were cut into 2.5 cm widths in the transverse direction, and the normal state (20°C, 65% PH) and water resistance strength and elongation were measured before and after heat treatment at 150°C for 3 minutes. In addition, the normal strength and elongation is determined by autographing the strength and elongation in the lateral direction (trial width 25 mm, trial length 100 mm, tensile speed 300 mm/
Water resistance and elongation were measured after immersion in water at 20°C for 30 minutes. Perchloren resistance strength and elongation were measured in the same manner as above after immersing the heat-treated web in perchlorethylene at 20°C for 60 minutes. The measurement results are shown in Table 1. Example 2 2 parts of polyvinyl alcohol with an average degree of polymerization of 500 and a degree of saponification of 88 mol% and 2 parts of nonyl phenyl ether (average degree of polymerization of ethylene oxide 20) were used as a protective colloid and a surfactant to produce vinyl acetate.
81.5 parts of ethylene, 18 parts of ethylene, and 0.5 parts of acrylic acid were polymerized using a hydrogen peroxide-tartaric acid catalyst to obtain an aqueous dispersion (A) with a viscosity of 83 cp, a solid content of 49.7%, and a pH of 7.0. Dispersed to a particle size of approximately 0.5μ per 100 parts of the dispersion.
Aqueous dispersion of carbamate amide of aziridine, the reaction product of MDI and ethyleneimine (B)
(solid content 25%) was added and mixed. (The number of moles of aziridine group per mole of carboxylic acid is 1.34 moles.) Water was added to the above composition to make an impregnation solution with a solid content of 3%, and the same treatment as in Example 1 was performed to measure the strength of the nonwoven fabric. . The results are shown in Table 1. Example 3 2 parts of polyvinyl alcohol with an average degree of polymerization of 500 and a saponification degree of 88 mol% and 2 parts of nonyl phenyl ether (average degree of polymerization of ethylene oxide 20) were used as a protective colloid and a surfactant to produce vinyl acetate.
80.8, 18.5 parts of ethylene, and 0.7 parts of itaconic acid are polymerized with a hydrogen peroxide-tartaric acid catalyst to produce a viscosity of 140 cp.
(BL.60rpm), solids content 49.8%, PH7.0 aqueous dispersion
I got (A). 3 parts of an aqueous dispersion (B) of carbamate amide of aziridine (solid content 25%), which is a reaction product of MDI and ethyleneimine, dispersed to a particle size of about 0.5 μ per 100 parts of the dispersion. part was added and mixed. (The number of moles of aziridine groups per mole of carboxylic acid is 0.86 moles.) This composition was diluted to a solid content of 3% and used as an impregnating solution to measure the performance of a polyester nonwoven fabric in the same manner as in Example 2. The results are shown in Table 1. Example 4 Table 1 shows the results of measuring the physical properties in the same manner as in Example 2 by adding 5 parts of the aqueous dispersion of aziridine carbamate amide and using it as a nonwoven fabric binder. (The number of moles of aziridine group per mole of carboxylic acid is 2.23 moles.) The performance is slightly improved compared to Example 2. This is thought to be due to an increase in the degree of crosslinking due to an increase in aziridine. Example 5 5 parts of nonyl phenyl ether (average degree of polymerization of ethylene oxide 20) was added as a surfactant, and 81 parts of vinyl acetate, 18.5 parts of ethylene, and maleic anhydride were added.
Polymerize 0.5 part of ammonium persulfate using Rongarit as an initiator to obtain a viscosity of 120 cp, solid content of 52.0%, and pH
An aqueous dispersion (A) of 7.0 was obtained. To 100 parts of the dispersion, 5 parts of an aqueous dispersion of aziridine carbamate amide (B) (solid content 25%), which is a reaction product of MDI and ethyleneimine dispersed to a particle size of about 0.5 μ, is added. and mixed to make an impregnating solution. (The number of moles of aziridine group per mole of carboxylic acid is 1.47 moles.) Using the impregnating solution, the web was treated in the same manner as in Example 1 and the strength of the web was measured. The results are shown in Table 1. Example 6 The composition of liquid (A) in Example 2 was changed to 88 parts of vinyl acetate, 11.5 parts of ethylene, and 0.5 parts of acrylic acid.
This is the case when the vinyl acetate ratio of the liquid increases. (The number of moles of aziridine group per mole of carboxylic acid is
It is 1.34 mol. ) The results are shown in Table 1. Example 7 The composition of solution (A) in Example 2 was changed to 71 parts of vinyl acetate, 28.5 parts of ethylene, and 0.5 parts of acrylic acid.
This is the case when the vinyl acetate ratio of the liquid decreases. (The number of moles of aziridine group per mole of carboxylic acid is
It is 1.34 mol. ) The results are shown in Table 1. Example 8 Solution (B) in Example 2 was replaced with a reaction product of methylene bis(4-phenyl isocyanate) (MDI) and ethyleneimine, and aziridine, a reaction product of p-xylylene diisocyanate and ethyleneimine, was used. An impregnating liquid was prepared using an aqueous dispersion (B) of carbamic acid amide. (The number of moles of aziridine group per mole of carboxylic acid is 1.65 moles.)
The results are shown in Table 1. Comparative Example 1 In Example 1, only liquid A was used as a binder for the polyester nonwoven fabric. Comparative Example 2 Solution A of Example 1 and oxime blocked methylene bis(4-phenyl isocyanate) (NCO content
3.82% (solid content: 30%) was used as a B liquid, and 3 parts of B liquid were mixed with 100 parts of A liquid and used as a binder for an ester nonwoven fabric. The phenyl isocyanate does not contain an aziridine group, but is a compound that contains a nitrogen atom and has crosslinking properties. Comparative Example 3 Vinyl acetate was prepared using 4 parts of polyvinyl alcohol with an average degree of polymerization of 500 and a degree of saponification of 88 mol% as a protective colloid.
Polymerize 81 parts and 19 parts of ethylene using ammonium persulfate as a catalyst, resulting in a viscosity of 120 cp, solid content concentration of 50.5%, and pH
An aqueous dispersion (A) of 7.0 was obtained. 3 parts of liquid B of Example 1 was added and mixed to 100 parts of the dispersion, and the mixture was used as a binder for an ester nonwoven fabric. The above Comparative Examples 1 to 3 are to show the effect of Example 1. Comparative Example 1 is the case where only the (A) liquid is used in Example 1 and the (B) liquid is omitted, and the Comparative Example 2 is ( B) This is a case where the liquid lacks an aziridine group, and Comparative Example 3 is
(A) This is the case where the liquid composition lacks carboxyl groups.
From the results in Table 1, there is a clear difference between Example 1 and these comparative examples in the effectiveness of heat treatment and in the water resistance and per-cleaning resistance of heat treatment. Comparative Example 4 Only Solution A of Example 2 was used as a binder for a polyester nonwoven fabric. Comparative Example 5 Solution A of Example 2 and oxime blocked methylene bis(4-phenyl isocyanate) (NCO content
3.82%, solid content 30%) was used as liquid B, and 3 parts were mixed with 100 parts of liquid A and used as a binder for ester nonwoven fabric. The above Comparative Examples 4 and 5 are to show the effect of Example 2. Comparative Example 4 is the case where only the (A) liquid is used in Example 2 and the (B) liquid is omitted, and the Comparative Example 5 is ( B) This is the case when the liquid lacks an aziridine group. From Table 1, it is recognized that Example 2 has significantly improved heat treatment effects and post-treatment water resistance and per-cleaning resistance compared to Comparative Examples 4 and 5. Comparative Example 6 The composition of solution (A) of Example 5 was polymerized with 82 parts of vinyl acetate and 18 parts of ethylene using an ammonium persulfate-Rongalite initiator, with a viscosity of 65 cp and a solid content of 50.0%.
In place of the aqueous dispersion of (B), the rest was the same as in Example 5.
The liquid was used as a binder for mixed ester nonwoven fabrics. This is the case where the solution (A) of Example 5 does not contain carboxylic acid, but Table 1 shows that there are differences in the heat treatment effect and the water resistance and perchloride resistance after treatment. Comparative Example 7 2 parts of hydroxyethyl cellulose and nonyl phenyl ether (polymer of ethylene oxide,
Average degree of polymerization 20) 4 parts were added as a protective colloid and surfactant, 84.5 parts of vinyl acetate, 12 parts of ethylene.
1 part, 3.5 parts of acrylic acid are copolymerized using ammonium persulfate as a catalyst, resulting in a viscosity of 26 cp and a solid content concentration of 36%.
An aqueous dispersion (A) was obtained. An aqueous dispersion (B) of carbamic acid amide of aziridine, which is a reaction product of 3-methylenebis(4-phenyl isocyanate) (MDI) with an average particle size of 0.5μ and ethyleneimine, is added to 100 parts of the dispersion (solid). 25%) was added and mixed. (The number of moles of aziridine groups per mole of carboxylic acid is 0.45 moles.) Water was added to this to prepare a dispersion liquid with a solid content of 3%, and the strength of the nonwoven fabric was measured in the same manner as in Example 1. Although the amount of unsaturated carboxylic acid in dispersion liquid (A) was set to be above the limit value, as is clear from the results of Example 6, although the degree of crosslinking is considered to be high, the heat treatment effect and It is observed that the water resistance and perchloride resistance after treatment are rather significantly reduced. Comparative Example 8 6 parts of polyvinyl alcohol with an average degree of polymerization of 500 and a saponification degree of 88 mol% and an average degree of polymerization of 1700 and a saponification degree of 88
A protective colloid was prepared by mixing 2 parts of polyvinyl alcohol (mol%), 99 parts of vinyl acetate, and 1 part of acrylic acid.
An aqueous dispersion (A) having a viscosity of 1850 c.p and a solid content of 46% was obtained by copolymerizing a portion of the dispersion. 3 parts of the dispersion (B) of Example 1 were added to 100 parts of the dispersion, mixed, and water was added to reduce the solid content to 4.
% dispersion was prepared, and then processed in the same manner as in Example 1 to prepare a nonwoven fabric. (The number of moles of aziridine group per mole of carboxylic acid is 0.75 moles.) When the dispersion (A) does not contain ethylene and only contains vinyl acetate, the adhesion to polyester fibers,
The strength was not measured because the film-forming property was extremely low and the performance as a nonwoven fabric was extremely poor.

【table】

[Table] Comparative Example 9 A polyester web was prepared in the same manner as in Example 1, except that the addition of 3 parts of an aqueous dispersion of aziridine carbamate amide (B) (solid content concentration 25%) in Example 1 was reduced to 0.4 parts. A nonwoven fabric was obtained using
(The number of moles of aziridine group per mole of carboxylic acid is 0.18 moles.) The strength and physical properties of the nonwoven fabric are shown in Table 2. It can be seen that when the aziridine group is 0.3 mole or less per mole of carboxylic acid, the crosslinking effect is small. Example 9 The strength and physical properties of the nonwoven fabric were measured in the same manner as in Example 2, except that the heat treatment conditions of 150° C. for 3 minutes in Example 2 were changed and the heat treatment was performed at 130° C. for 3 minutes. The results are shown in Table-2. Comparative Example 10 For 100 parts of the aqueous dispersion (A) used in Example 2,
Aqueous dispersion of aziridine carbamate amide (B)
Instead, 5 parts of solid content of hexamethoxymethylmelamine resin ("Cymel 310" manufactured by American Cyamide) and 2 parts of a 10% ammonium chloride aqueous solution were added. A polyester web was impregnated with this composition in the same manner as in Example 2 at a concentration of 20% (solid content)/fiber weight, and dried at 60°C for 30 minutes. After cutting the test piece, heat treatment was performed at two levels: 150°C for 3 minutes and 130°C for 3 minutes, and the strength and physical properties of the nonwoven fabric were measured. The results are shown in Table-2. It can be seen that when a melamine resin is used as a crosslinking agent, when the heat treatment temperature is lowered, the crosslinking effect is significantly lower than that of an aziridine resin.

[Table] Example 10 Nonyl phenyl ether (average degree of polymerization of ethylene oxide 10) 4 parts of sodium sulfate was added as a surfactant, 79 parts of vinyl acetate, 20 parts of ethylene, 1 part of acrylic acid and ammonium persulfate-Rongalit was used as an initiator. Polymerized with viscosity 260 cp, solid content
An aqueous dispersion (A) of 53.0% and pH 6.0 was obtained. The dispersion liquid
An impregnating solution was prepared by adding and mixing 1.6 parts of the aziridine carbamate amide aqueous dispersion (B) used in Example 1 to 100 parts. (The number of moles of aziridine group per mole of carboxylic acid is 0.34 moles.) Using the impregnating solution, the web was treated in the same manner as in Example 1 and the strength of the web was measured. The results are shown in Table-3. Comparative Example 11 A nonwoven fabric was obtained in the same manner as in Example 4, except that the amount of the aqueous dispersion (B) of aziringine carbamate amide was increased to 24 parts instead of 5 parts in Example 4. (The number of moles of aziridine group per mole of carboxylic acid is 10.7 moles.) The strength properties are shown in Table 3. White powder, which was thought to be powder of an aziridine compound, was adhered to the surface layer of the nonwoven fabric, and the appearance was poor. As mentioned above, even if 10 moles or more of the aziridine compound is added to 1 mole of carboxylic acid, no further improvement in physical strength is observed compared to the addition amount of 0.3 to 10 moles, and on the contrary, the film forming property is It can be seen that the aziridine compound without the aziridine impairs other physical properties (appearance, texture, etc.).

【table】

Claims (1)

[Scope of Claims] 1 Ethylenically unsaturated monocarboxylic acid or ethylenically unsaturated polycarboxylic acid with an ethylene content of 8 to 30% by weight and a vinyl acetate content of 92 to 70% by weight
An aqueous dispersion of a compound having two or more aziridine groups in the molecule in an aqueous dispersion (A) of a copolymer copolymerized with 0.1 to 3.0 parts by weight based on 100 parts by weight of ethylene/vinyl acetate copolymer. (B), and the amount of aziridine groups in the aqueous dispersion (B) of a compound having two or more aziridine groups in the molecule relative to the amount of carboxylic acid in the aqueous copolymer dispersion (A). The amount ratio is aziridine group/carboxylic acid = 0.3 mol to 10 mol/
A fiber binder characterized in that the amount is 1 mol.