JP2905499B2 - Highly foamed water-based adhesive composition for carpet and carpet coated with the composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel high foaming water-based adhesive composition for carpet, and a carpet obtained by coating the composition. More specifically, the present invention improves carpet handling and productivity by maintaining high adhesive strength, significantly increasing the foaming ratio, and reducing the coating weight of the carpet. The present invention relates to a high-foaming water-based adhesive composition for carpets capable of reducing costs and a carpet obtained by applying the composition.

2. Description of the Related Art Conventionally, a water-based adhesive composition is usually applied to a carpet in order to fill irregularities of the raw material. This water-based adhesive composition generally contains, as necessary, an aqueous latex, a dispersant, an antioxidant, an antiseptic, an antifoaming agent, a crosslinking agent, a blister-resistant agent, and the like, and an inorganic filler and After adding a thickener to adjust the viscosity to be suitable for flowability, it is applied as it is (without foaming) to a rough carpet raw material by a coater.

However, in such a method, a large amount of an aqueous adhesive composition is required to fill the irregularities of the carpet raw material, and this tendency is particularly large in a large pile carpet raw material. When the coating weight is large, the overall weight of the carpet becomes heavy, which deteriorates handleability, and causes problems such as inevitable increase in cost and decrease in productivity.

Therefore, as a method of reducing the coating weight of the water-based adhesive composition, the composition is mechanically stirred to increase the volume by forcibly mixing air to reduce the coating weight on the rough carpet raw material. Attention has been paid to a foaming (floss) coating method (Japanese Patent Publication No. 48-9829), and an aqueous adhesive composition for carpet which is effective for such a foaming coating method (Japanese Patent Application Laid-Open No. 63-227875). ) Has also been proposed.

However, in the conventional water-based adhesive composition,
When the foaming ratio is increased, when applied to a carpet, there is a disadvantage that the cohesive force of the adhesive layer is reduced and the adhesive strength such as the pull-out strength and peel strength of the pile is inevitably reduced. For example, JP-B-48-9829 discloses a carpet coated with a water-based adhesive composition foamed so as to have a foaming ratio of 1.7 to 3 times (specific gravity of 0.85 to 0.50) in the examples. have been, in order to obtain the desired bond strength by bonding secondary backing, the foaming magnification of the composition is kept low and 1.7 times, as the coating amount is 969 g / m ² Used in large quantities.

As described above, in the conventional foam coating method, in order to obtain a desired adhesive strength, the foaming ratio of the aqueous adhesive composition cannot be increased, and the capacity is reduced to about 1.1 to 2.0 times at most. It is only increased, as a result, the coating weight of the aqueous adhesive composition is limited to about 2/3,
The fact is that cost reduction and productivity increase are not as effective as expected.

Problems to be Solved by the Invention The present invention overcomes such disadvantages in the prior art, while maintaining a high adhesive strength, significantly increasing the foaming ratio, and reducing the coating weight of the carpet, A high-foaming water-based adhesive composition for carpets that improves the handleability and productivity of the carpet and enables significant cost reduction, and a carpet formed by applying the composition. It is.

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, the aqueous latex has a toluene insoluble content of a specific ratio or more as a composition component, and is subjected to defoaming treatment. The maximum tensile strength of the obtained dried film is in a specific range, and it has been found that the object can be achieved by a high-foaming water-based adhesive composition foamed so as to have a specific foaming ratio. The present invention has been completed based on the findings.

That is, the present invention comprises (A) an aqueous latex having a toluene-insoluble content of 50% by weight or more, (B) a foaming agent, (C) an inorganic filler, and (D) a thickener as essential components. A high-foaming water-based adhesive composition for carpets, characterized in that the dried film obtained by the treatment has a maximum tensile strength of 25 kg / cm ² or more and is foamed so that the foaming ratio becomes 2.0 to 4.0 times. And a carpet obtained by applying the composition to a carpet raw material.

 Hereinafter, the present invention will be described in detail.

In the composition of the present invention, in the aqueous latex used as the component (A), the content of the toluene-insoluble component in the polymer may be either the case where the crosslinking agent is not added or the case where the crosslinking is performed after heat treatment with the addition of the crosslinking agent. In this case, it is necessary that the content is 50% by weight or more. When the content of the toluene-insoluble component is less than 50% by weight, the maximum tensile strength of the dried film of the composition is low, and sufficient adhesive strength cannot be obtained.

Further, the glass transition temperature of the polymer is preferably in the range of -30 to + 40C. This glass transition temperature is -30
When the temperature is lower than 0 ° C, the maximum tensile strength of the dried film of the composition does not increase, and the adhesive strength of the carpet is insufficient. When the temperature exceeds 40 ° C, the texture of the obtained carpet tends to be hard, which is not preferable.

When a polymer having a low glass transition temperature is used, it is desirable that the content of the toluene-insoluble component is higher.

Examples of the aqueous latex include styrene-butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, and styrene-butadiene- latex.
Methyl methacrylate copolymer latex, styrene-
Butadiene-butyl acrylate copolymer latex,
Examples include styrene-butyl acrylate copolymer latex, acrylonitrile-butadiene copolymer latex, and ethylene-vinyl acetate copolymer latex. Further, a latex containing a monomer unit having an active group such as a carboxyl group, a glycidyl group, an amide group, a hydroxyl group, or an N-methylol group in the copolymer can also be used. Among these latexes, in particular, carboxy-modified styrene-butadiene copolymer latex and carboxy-modified styrene-butadiene- latex
Methyl methacrylate copolymer latex is preferred. These aqueous latexes may be used alone or in combination of two or more.

In the above-mentioned aqueous latex, when the glass transition temperature of the polymer is in the range of −10 to + 35 ° C., taking a styrene-butadiene copolymer latex as an example, the content of butadiene units in the copolymer is about 25%. 4545% by weight.

In the composition of the present invention, examples of the foaming agent used as the component (B) include alkyl sulfates such as sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate, sodium myristyl sulfate, and sodium caprylsulfate. System, sodium polyoxyethylene lauryl sulfate,
Alkyl ether sulfates such as ammonium polyoxyethylene lauryl sulfate, triethanolamine polyoxyethylene lauryl sulfate, sodium polyoxyethylene oleyl ether sulfate, polyoxyethylene myristyl ether sulfate triethanolamine, alkyl benzene sulfonate, alkyl naphthalene sulfonate , Sulfonates such as alkyl sulfosuccinates and alkyl diphenyl ether disulfonates, fatty acid salts such as sodium stearate, ammonium stearate, sodium myristate, potassium oleate, potassium palmitate, ammonium laurate, or alkyl phosphorus Anionic surfactants such as acid salts, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl sulfate Vinyl ether, lauric acid monoethanolamide, monoethanolamide stearate
Examples include nonionic surfactants such as lauric acid isopropanolamide and coconut oil fatty acid diethanolamide, and amphoteric surfactants such as betaine and cationic surfactants such as amine. One of these foaming agents may be used, or two or more thereof may be used in combination. This foaming agent may be used when producing the aqueous latex of the component (A), and the one contained in the aqueous latex may be used as it is, or may be added when the composition is prepared. You may.

Regarding the addition amount of the foaming agent, the larger the addition amount of the inorganic filler of the component (C), the larger the amount of the foaming agent adsorbed by the filler. It is necessary to increase the amount of the foaming agent added. In addition, compared to the amount of the foaming agent in the adhesive composition used in the conventional foam coating method, the amount of the foaming agent used in the composition of the present invention is a foaming property and foam stability. It is advantageous to increase from above.

In the composition of the present invention, examples of the inorganic filler used as the component (C) include calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, titanium oxide, and barium sulfate. These inorganic fillers may be used alone or in combination of two or more.

Regarding the blending amount of the inorganic filler, it is desirable that the blending ratio of the (A) component to the aqueous latex is close to the critical filler volume concentration (PVC), and the filler volume concentration is in the range of 35 to 60%. It is preferable to mix them. The amount in this range corresponds to 150 to 400 parts by weight per 100 parts by weight of the aqueous latex when, for example, heavy calcium carbonate commonly used as an inorganic filler is used. If the welding concentration is less than 35%, the blister resistance is inferior and economically disadvantageous. If it exceeds 60%, the cohesive strength of the adhesive composition is reduced, and the bonding strength of the carpet is reduced. Not preferred.

Furthermore, in the composition of the present invention, examples of the thickener used as the component (D) include sodium acrylate, carboxymethylcellulose, hydroxymethylcellulose, methylcellulose, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, and blocked alkyl polyether. Water-soluble polymer compounds can be mentioned. One of these thickeners may be used, or two or more of them may be used in combination.

In the composition of the present invention, a crosslinking agent can be added as required for the purpose of increasing the maximum tensile strength of the dried film and improving the adhesive strength. The addition of the crosslinking agent is particularly effective for aqueous latexes having an active group in the polymer, since the crosslinking agent reacts with the polymer of the aqueous latex to cause crosslinking.

Examples of such a crosslinking agent include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerin diglycidyl ether, N,
N, N ', N'-tetraglycidyl m-xylenediamine,
Compounds having two or more glycidyl groups such as 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, diphenylmethanebis-4,4'-N, N'-diethylene urea,
Compounds having an ethyleneimine group such as p-phenylenebis-N, N'-ethyleneurea and m-toluylenebis-N, N'-ethyleneurea; compounds having an isocyanate group such as block isocyanate; modified polyamide resin; oxazoline And a compound having a methylol group. One of these crosslinking agents may be used, or two or more thereof may be used in combination.

In the high-foaming water-based adhesive composition of the present invention, the dry film obtained by the defoaming treatment needs to have a maximum tensile strength of 25 kg / cm ² or more. The maximum tensile strength of a dried film of an aqueous adhesive composition conventionally used for carpet is usually 10 to 20.
Those having a weight of about kg / cm ² and 25 kg / cm ² or more, together with the amount of coating, had an excessively hard texture and were hardly used.

In the present invention, when the maximum tensile strength of the dried film is 25 kg / cm ² or more, even when foaming is performed at a high foaming ratio, the cohesive force of the adhesive layer of the carpet is maintained, and the adhesive strength is not reduced, and Since the amount of coating can be greatly reduced, the texture of the carpet can also be maintained at an appropriate softness. The method of measuring the maximum tensile strength of the dried film will be described later.

When the maximum tensile strength of the dried film is less than 25 kg / cm ² , when applied to a carpet raw material in a high foaming state, the cohesive force of the adhesive layer after drying is low, and sufficient adhesive strength cannot be obtained, so that it is practical. Not.

In the composition of the present invention, it is necessary to foam so that the foaming ratio is in the range of 2.0 to 4.0 times, preferably 2.5 to 3.5 times. If the foaming ratio is less than 2.0 times, it is easy to increase the adhesive strength of the carpet, but the effects of carpet cost reduction and productivity improvement are not sufficiently exhibited, and the
If it exceeds twice, the cohesive strength of the adhesive layer after processing and drying will decrease,
The adhesive strength tends to be low.

When the foaming ratio is set to 2.0 to 4.0 times, the coating weight can be relatively reduced to 2/3 to 1/3 of the normal weight even when applied to a carpet raw material having irregularities, and as a result, the drying speed is 1.5. Can be up to 3.0 times. The reason why the coating weight is not inversely proportional to the foaming ratio is that when the carpet raw material is applied, a foaming phenomenon of the foamed water-based adhesive occurs, resulting in a decrease in capacity.

There is no particular limitation on the foaming method of the composition, and a method conventionally used for foaming an aqueous adhesive can be used.For example, the supply capacity of the composition can be determined using a so-called floss machine. The ratio between the air volume and the air volume may be appropriately selected so that the foaming ratio is in the range of 2.0 to 4.0 times, and the air may be mechanically mixed to foam.

The carpet high foaming water-based adhesive composition of the present invention,
Within the scope not detracting from the object of the present invention, if necessary, for example, a dispersant, an antifoaming agent, a flame retardant, an antioxidant, an antistatic agent, an antibacterial / antibacterial agent, a pH adjusting agent, a chelating agent, A blister-resistant agent, a water-resistant agent and the like may be added. However, it is desirable not to use an antifoaming agent as much as possible. If the addition amount is large, the foaming property may be impaired. In addition, as for the anti-blister agent, the composition of the present invention has a high foaming ratio, so it is not so necessary.However, in the case of a low solid content and a low foaming ratio, the addition of the agent prevents the generation of blisters, This is advantageous because productivity can be increased.

In the composition of the present invention, the viscosity before foaming at room temperature is
It is desirably in the range of 15,000 to 40,000 cps, preferably 2,000 to 35,000. If the viscosity before foaming is less than 15000 cps, the penetration into the carpet raw material is large, and the foaming property is also poor, and if it exceeds 40,000 cps, the fluidity is reduced and coating unevenness tends to occur, and the foaming device is used. The supplied air pressure becomes too high, making it difficult to achieve a desired foaming ratio.

The solid content in the composition is usually selected in the range of 60 to 85% by weight, preferably 65 to 83% by weight. If the solid content is less than 60% by weight, the moisture content is too high, the drying efficiency is low, and the productivity of the carpet is poor. If the solid content is more than 85% by weight, the viscosity adjustment is difficult, and in some cases, the composition thickens. It is not preferable because foaming cannot be performed or coating unevenness is likely to occur.

By applying such a high foaming water-based adhesive composition to a carpet raw material, a carpet of the present invention having high adhesive strength can be obtained.

The method for applying the composition is not particularly limited, and a method conventionally used for application to a raw carpet material can be used. For example, it may be usually applied by a roll coater, or may be directly applied to a raw carpet material,
Any of a single coating method, a double coating method, a double separation coating method, and the like can be used.

Furthermore, the coating weight cannot be determined unequivocally because the degree of unevenness of the coating surface varies depending on the type of carpet raw material (the number of gauges, pile height, basis weight, etc.). When compared with the materials, the high-foaming water-based adhesive composition of the present invention is 2 /
Only about 3 to 1/3 is needed.

Effect of the Invention The high foaming water-based adhesive composition for carpet of the present invention has a high adhesive strength and a greatly increased foaming ratio, and can reduce the coating weight on a carpet. Since it is possible to improve the handleability and productivity of the carpet, and has a feature of enabling a significant cost reduction, the carpet formed by applying this composition is lightweight. In addition, it has high commercial value such as high adhesive strength.

Examples Next, the present invention will be described in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

In addition, each characteristic in the example and the comparative example was determined according to the following method.

(1) Maximum tensile strength of the dried film After the water-based adhesive composition was degassed by reducing the pressure to 730 mmHg or less, it was cast on a Teflon plate with an applicator having a clearance of 1 mm, at a temperature of 23 ° C and a relative humidity of 60%. And dry for at least one day. After heat-treating this dried film at 90 ° C. for 15 minutes, the film is left for 1 day or more at a temperature of 23 ° C. and a relative humidity of 60%, and then subjected to measurement.

The dried film is made into a 10 mm-wide tank, set in a tensile tester, and measured under the conditions of a distance between chucks of 50 mm, a tensile speed of 100 m / min, a temperature of 23 ° C. and a relative humidity of 60%.

(2) Foaming ratio This is a value obtained by dividing the specific gravity of the composition before foaming by the specific gravity of the composition after foaming.

(3) Peeling strength and pile pull-out strength After the carpet sample was allowed to stand in a constant temperature room at 23 ° C. and 60% RH for 24 hours or more, it was measured according to a rug test method (JIS L-1021).

(4) Texture From the carpet sample, cut out a test piece of 10 × 20cm and bend the long direction of this test piece to make 10 mm between both ends in the short direction.
The bending stress of the carpet at a distance of cm was used as a measure of hand. The larger the value, the harder the texture.

(5) Viscosity (room temperature) of the composition before the initiation using a Brookfield-type rotational viscometer (BM type)
The measurement was performed at a rotation speed of 12 rpm using a No. 4 rotor.

Examples 1 to 5 and Comparative Examples 1 to 6 To 100 parts by weight of various aqueous latexes obtained from the monomer compositions shown in Table 1, a foaming agent of the type and amount shown in Table 2 was added, and further dispersed. After adding 1 part by weight of sodium tripolyphosphate as an agent, heavy calcium carbonate (SS-30, manufactured by Nitto Powder Chemical Co., Ltd.) as an inorganic filler was added in an amount shown in Table 2. Next, after the heavy calcium carbonate was sufficiently dispersed, sodium polyacrylate as a thickener was added in the amount shown in Table 2 to increase the viscosity (room temperature) to 3,000 ±.
An aqueous adhesive composition having a solid content shown in Table 2 was prepared by adjusting to 1000 cps. In each of the examples, 1 part by weight of an antioxidant was added, and
In Comparative Example 5 and Comparative Example 5, 1 part by weight of glycerin diglycidyl ether as a crosslinking agent was added. Next, using 300 g of the water-based adhesive thus obtained, using a desktop type Hobart mixer Model 5SS (manufactured by Hovard, with whip blades), mechanically mix air at a rotation speed of 220 rpm, and stir. By adjusting the time, a foamed water-based adhesive composition having the foaming ratio shown in Table 2 was obtained.

This foamed water-based adhesive composition was uniformly applied to a carpet raw material obtained by tufting BCF nylon on a primary base cloth of polypropylene so as to have a coating weight shown in Table 2, and then a 7 oz. The next base cloth is laminated and dried at 130 ° C. using a hot air circulating drier, and dried until the water content of the composition becomes 5% by weight or less. A coated carpet was produced. The drying time at this time was determined.

With respect to the carpet thus obtained, the peel strength, the pile pull-out strength and the texture were evaluated. Table 2 shows the results.

(Note) Types of foaming agents a: sodium lauryl sulfate b: triethanolamine lauryl sulfate c: sodium dodecylbenzenesulfonate e: polyoxyethylene lauryl ether triethanolamine sulfate f: polyoxyethylene nonyl phenyl ether

Continuation of the front page (51) Int.Cl. ⁶ identification symbol FI // D06M 17/00 D06M 17/00 C (58) Field surveyed (Int.Cl. ⁶ , DB name) D06M 15/00-15/715 D06M 17/00

Claims (3)

(57) [Claims] 1. A defoaming treatment comprising (A) an aqueous latex having a tunnel insoluble content of 50% by weight or more, (B) a foaming agent, (C) an inorganic filler, and (D) a thickener as essential components. The high foaming water-based adhesive composition for carpets, characterized in that the dried film obtained by the above method has a maximum tensile strength of 25 kg / cm ² or more and is foamed so that the foaming ratio becomes 2.0 to 4.0 times. Stuff. 2. The high foaming water-based adhesive composition for carpet according to claim 1, wherein the foaming is performed so that the foaming ratio becomes 2.5 to 4.0 times. 3. A carpet obtained by applying the composition according to claim 1 to a raw carpet material.