JPH0299672A - Production of carpet - Google Patents

Abstract

PURPOSE:To obtain a carpet having a high stitch extraction and peel strength by coating a base fabric with a backing composition, consisting of a copolymer latex prepared by carrying out emulsion polymerization of a specific monomer and an inorganic filler and excellent in drying properties and blister resistance. CONSTITUTION:An inorganic filler in an amount of 100-750 pts.wt. based on 100 pts.wt. (solid content) copolymer latex is added to the copolymer latex with 40-98wt.% content of portions insoluble in toluene and 700-3000Angstrom average particle diameter prepared by carrying out emulsion polymerization of (A) 25-65wt.% one or more monomers selected from aliphatic conjugated diene-based monomers, acrylic acid esters having a 2-10C alkyl group and/or methacrylic acid esters having a 6-14C alkyl group with (B) 0.5-8wt.% ethylenically unsaturated carboxylic acid monomer [preferred example; (meth)acrylic acid] and (C) 27-74.5wt.% other monomers (preferred example; styrene) copolymerizable therewith to afford a backing composition for a carpet. The resultant composition is applied to a carpet base fabric to provide the objective carpet, rapidly predryable with steam and having a high stitch extraction strength, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a carpet, and more specifically,
The present invention relates to methods of making carpets backed with certain carpet backing compositions.

[Prior Art] Conventionally, carpet backing compositions are made by adding an inorganic filler and, if necessary, a dispersant, an aging stabilizer, an antifoaming agent, a foaming agent, a crosslinking agent, etc. to a copolymer latex to create a rough texture. It is manufactured by adjusting the viscosity to an appropriate level using a thickener.

Such carpet backing compositions are applicable to all backed carpets such as tufted, knitted or hooked carpets. In addition, as a backing method in this case, for example, in the case of tufted carpet, 1q of tufted yarn such as crimped nylon yarn or crimped polyester yarn is tufted onto a primary base fabric such as polypropylene, and the carpet is placed on the back side of the gray fabric. A tufted carpet is made by applying the backing composition and drying it with hot air, or by applying the composition and then laminating a secondary base material such as jute HIT'i or synthetic fiber nonwoven fabric and drying it with hot air. .

Therefore, the required characteristics of a carpet backing composition include high removal strength of the tufted yarns in the manufacturing process or product and high peeling strength of the primary base fabric and secondary base fabric, good drying efficiency in the drying process, and Things such as blister resistance (no blisters) are required.

[Problems to be Solved by the Invention] Unfortunately, no conventional carpet backing composition has been found that satisfies all of the above-mentioned required properties.

In particular, in recent years, in order to increase productivity in the carpet processing manufacturing process, a drying method has been adopted in which large dryers are used to speed up the carpet running inside the dryer under conditions of high temperature and high air volume. Problems have arisen in blister resistance, deterioration in thread removal strength due to insufficient drying, or deterioration in peel strength between the primary base 15 and the secondary base fabric. To solve this problem, a carpet backing composition with good blister resistance and drying properties is desired, and a method has been proposed to increase the concentration of solid components in the composition. The fluidity, dispersibility and viscosity stability of fillers deteriorate, and the above problems have not yet been satisfactorily solved. In addition, this method requires a high concentration of the copolymer latex, and there are also problems in the production of the copolymer latex. That is, in order to increase the concentration of the composition, for example, it is necessary to increase the particle size of the copolymer latex constituting the composition to lower the viscosity, but as a result, coagulation occurs during the polymerization process. It becomes a big problem.

An object of the present invention is to solve the above-mentioned conventional technical problems and provide a method for manufacturing a carpet that has high thread extraction strength and peel strength, and has good drying efficiency and blister resistance in the drying process.

[Means for solving the problem] In order to achieve the above objective, as a result of intensive research into the mechanism of carpet blistering, the cause of blistering was found to be due to a sudden increase in humidity in the dryer of the carpet backing composition. The cause was found to be the migration of latex and inorganic fillers due to a decrease in viscosity, and the formation of a film on the surface layer, causing moisture that had no place to escape to boil and form blisters.

Therefore, it has been found that in order to prevent blistering, it is necessary to prevent migration of the carpet backing composition and prevent formation of a film on the surface.

Other methods for improving blister resistance include adding organic polysiloxane to the carpet backing composition (Japanese Patent Publication No. 56-14191) and adding starch (Japanese Patent Application Laid-open No. 126242-1982). has been proposed, but it has not yet achieved sufficient blister prevention.
Furthermore, there are problems with the stability over time, decomposition, etc. of carpet backing compositions, and they are still unsatisfactory.

In the present invention, after applying a specific carpet backing composition to carpet greige, the applied surface is heated with steam to raise the temperature of the applied composition, thereby preventing a rapid temperature rise of the composition in the subsequent hot air dryer. It has been found that carpet backing composition migration and surface film formation can be avoided. As a result, by improving blister resistance, drying properties, and initial peeling strength with the secondary base fabric, it is possible to prevent curling (preventing the occurrence of defective products). Obtained. Furthermore, we were able to obtain excellent performance with carpets made by pasting jute onto raw fibers such as big pile and graphic pile.

In other words, the present invention provides (a) an aliphatic co-1Ω diene monomer, Nisder acrylate having an alkyl group having 2 to 10 carbon atoms, and/or methacrylic acid having an alkyl group having 6 to 14 carbon atoms; Copolymerizable with 25 to 65% by weight of one or more monomers selected from acid esters, (b) 0.5 to 4% by weight of an ethylenically unsaturated carboxylic acid monomer, and (c) these. 40 to 98% by weight of toluene insoluble matter obtained by emulsion polymerization with 27 to 74.5% by weight of other monomers,
100 to 75 parts by weight of inorganic filler per 100 parts by weight of copolymer latex (solid content) with an average particle diameter of 700 to 3000 Å
The present invention provides a method for producing a carpet, which comprises applying a carpet backing composition containing 0 parts by weight to a gray fabric, preheating it with steam, and then main drying it in a hot air dryer.

In the present invention, the copolymer latex (a
) component aliphatic conjugated diene monomers include 1,
Examples include 3-butadiene, isoprene, 2-chloro-1,3-butadiene, and among these, 1,3-butadiene is preferred. As the acrylic ester having an alkyl group having 2 to 10 carbon atoms, ethyl acrylate,
Examples of the methacrylate ester having an alkyl group having 6 to 14 carbon atoms include butyl acrylate and 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate and lauryl methacrylate. These aliphatic conjugated diene monomers, acrylic esters, and methacrylic ester monomers can be used alone or in combination of two or more.

These monomers are essential components for imparting appropriate flexibility and adhesive strength to the resulting copolymer latex.
Its proportion is 25 to 65% by weight in the copolymer latex raw material.
, preferably 30 to 60% by weight. If the weight is less than 25% by weight, the flexibility and adhesive strength will be poor, while if it exceeds 65% by weight, the stability of the resulting latex will be poor, the carpet will be too soft, and the peel strength will be low.

The (b) ethylenically unsaturated carboxylic acid monomer used in the present invention includes, for example, itaconic acid, acrylic acid,
Examples include methacrylic acid, fumaric acid, and maleic acid. These ethylenically unsaturated carboxylic acid monomers can be used alone or in combination of two or more, but a combination of appropriate amounts of acrylic acid and methacrylic acid is preferred.

The period of use of ethylenically unsaturated carboxylic acid monomer is 0.5~
8% by weight, preferably 0.7-7.5% by weight. 0
．． If it is less than 5% by weight, the stability of the latex during polymerization is poor and coagulation is likely to occur, the mechanical and chemical stability of the resulting latex is poor, and the resulting carpet backing composition shows changes over time. Undesirable. On the other hand, if it exceeds 8% by weight, the resulting latex will have a high viscosity and poor stability, making it impractical.

Furthermore, (c) other monomers copolymerizable with each of the above monomers include aromatic vinyl compounds, vinyl cyanide compounds, vinyl acetate, acrylamide, and alkyl methacrylates having 1 to 5 carbon atoms, preferably Examples include methyl methacrylate.

Among these, examples of aromatic vinyl compounds include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and chlorostyrene, with styrene being particularly preferred.

Furthermore, examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, and the like, and among these, acrylonitrile is preferred. These other monomers can be used alone or in combination of two or more. Particularly, copolymerization using methyl methacrylate as the other monomer is suitably applied since the polymerization stability can be significantly improved.

The amount of these (c) (t!! monomers used is 27 to 74.F4i% in the copolymer latex raw material, preferably 3
It is 0 to 69.5i amount%. A carpet backing composition using a latex with a weight of less than 27% by weight will result in a carpet that is too soft in feel, whereas if it exceeds 74.5% by weight, it will become too hard, causing problems in handling and construction. The main physical properties of the carpet, such as back yarn strength and peel strength from the secondary base fabric, are poor.

In the present invention, a copolymer latex is first obtained by emulsion polymerization of each of the above monomers, and the emulsifiers include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium diphenyl ether disulfonate, and succinic acid. One or more of anionic emulsifiers such as sodium dialkyl ester sulfonate, or nonionic emulsifiers such as polyoxyethylene alkyl ester and polyoxyethylene alkyl allyl ether can be used. In particular, sodium diphenyl ether disulfonate can be mentioned as an emulsifier that can significantly exhibit the effects of the present invention.

The amount of emulsifier used is usually 0.2 to 4.01i%, preferably 0.5 to 3%, based on the total weight of the monomers.
．． It is 0% by weight. If the amount of emulsifier used is too small, polymerization stability will deteriorate, such as the generation of coagulated products, while if the amount used is too large, the average particle size of the copolymer latex will become small, which may cause problems in the production of carpet backing compositions. The dispersibility of the filler described later becomes poor, and the viscosity changes over time after being blended.

Chain transfer agents used to lower the degree of polymerization in the polymerization reaction and cause an almost ideal chain transfer reaction include t-dodecyl mercaptan, n-tetradecyl mercaptan, octyl mercaptan-hexyl mercaptan. Mercaptans such as, carbon tetrachloride, halogenated compounds such as ethylene bromide are usually used.
O~0.5ffli% is used.

In general, polymerization initiators include per@-acid initiators such as sodium persulfate, sodium persulfate, and ammonium persulfate, cumene hydroperoxide, isopropylbenzene hydroperoxide, paramenthane hydroperoxide, and benzoyl. Organic peroxides such as peroxide, hydrogen peroxide, etc. may be used, but when cumene hydroperoxide is used in particular, a copolymer latex with excellent drying efficiency, which is the object of the present invention, can be obtained. The use of such a polymerization initiator is preferably 0.03 to 2.5
The amount is preferably 0.05 to 2.0% by weight.

In order to accelerate the emulsification process, reducing agents such as sodium pyrobisulfite, sodium sulfite, sodium bisulfite, ferrous sulfate, glucose, sodium formaldehyde sulfoxylate, ascorbic acid, sodium hydrogen sulfite, glycine, etc. , alanine, sodium ethylenediaminetetraacetate, and other chelating agents can also be used in combination.

In the emulsion polymerization, in addition to the emulsifier, chain transfer agent, polymerization initiator, etc., various electrolytes, pH adjusters, etc. are used in combination as necessary, and for example, 100 parts by weight of the monomers (a) to (c) are added. In contrast, 100 to 300 parts by weight of water, the emulsifier, chain transfer agent, polymerization initiator, etc. are used within the above range, the polymerization humidity is 5 to 80'C, preferably 30 to 50'C, and the polymerization time is 15 to 30°C. The polymerization is carried out under conditions such that the average particle size in the resulting copolymer latex is 700 to 3,000 particles, preferably 750 to 2,800 particles. If the average particle diameter obtained is less than 700, the blister resistance is poor;
Also, the viscosity of the carpet backing composition changes over time.

On the other hand, if it exceeds 300 OA, it will be necessary to use a large amount of thickener, which is not preferable in terms of cost. Furthermore, the fluidity of the carpet backing composition decreases, resulting in poor workability.

The method of adding each of the monomers (a) to (c) during emulsification is not particularly limited, and any method such as the diluted addition method, continuous addition method, or divided addition method may be employed.

The polymerization conversion rate of the obtained copolymer latex was 99.0%.
It is preferable that it is above.

Note that the average particle diameter of the copolymer latex is determined by treating the copolymer latex with osmic acid at a magnification of 30,
It is determined by taking an electron micrograph at 1,000 times magnification, measuring the diameters of 100 particles, and averaging them by number.

The toluene insoluble content of copolymer latex is 40 to 98 Fw
%, preferably 50-9.1%. If it is less than 1%, the drying properties and peel strength will be poor, while if it exceeds 98%, the peel strength and suture removal strength will be poor.

The toluene-insoluble content was measured by the method shown in Examples.

The carpet backing composition of the present invention generally has a viscosity of 20,000 to 40,000 cps, preferably 25,000 to 35,000 cps, and a solids concentration of 55 to 85% by weight, preferably 60 to 80% by weight.
It is prepared by adding a thickener and, if necessary, water to achieve a heavy viscosity.

If the viscosity is less than 20,000 cps, the permeability into the carpet will be high and the peel strength will be low. On the other hand, 4
If it exceeds 0.0OOcps, coating properties will deteriorate and unevenness will occur. In addition, if the solid content concentration is less than 55% by weight, there is too much moisture and the drying efficiency is poor, resulting in a decrease in yarn strength and peel strength, whereas if it exceeds 85% by weight, drying properties may be improved The viscosity of the composition increases, resulting in poor coating efficiency and uneven coating, resulting in variations in quality such as peel strength and texture.

Next, the fillers used in the present invention include inorganic fillers such as calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, barium sulfate, silicic acid, silicate, titanium oxide, magnesium carbonate, and calcium carbonate. Examples include, but are not limited to, agents. These fillers can be used alone or in combination of two or more.

The proportion of the copolymer latex and filler used is about 100 to 750 parts by weight, preferably about 150 to 700 parts by weight, per 100 parts (solid content) of the latex. If the filler amount is less than 100 parts by weight, the blister resistance will be poor, and if it exceeds 750 parts by weight, the peel strength will be poor.
This is not preferred because the strength of the back yarn and drying properties are poor.

As described above, the carpet backing composition of the present invention has a copolymer latex and an inorganic filler as main components, but may also include a dispersant, an antifoaming agent, a crosslinking agent, a blowing agent, a coloring agent, and a coloring agent as necessary. agents, flame retardants, preservatives, anti-aging agents, stabilizers,
Vulcanization accelerators, antistatic agents, pH adjusters, etc. can be added.

The effects of the carpet backing composition described above are as follows:
This can be achieved by applying the method to gray carpet, which will be described later, and performing steam preheating and main drying, thus solving the conventional problems.

Next, the drying system of the present invention will be explained.

As shown in FIG. 1, the carpet drying system of the present invention preheats the applied composition with steam immediately before hot air drying, unlike the conventional method. In FIG. 1, 1 is a carpet greige, 2 is a compound bath, 3 is a backing composition, 4 is a secondary base fabric, 5 is a steam heating machine, 6 is a hot air dryer, and 7 is a rolled up carpet.

As conditions for preheating with steam, it is preferable to blow steam onto the composition from the bottom to the top.

That is, the desired effect of the present invention can be achieved by using the above specific backing composition as a carpet backing agent,
This can be achieved by satisfying both conditions of a drying process in which main drying is performed after heating with steam.

The drying system, which is a feature of the present invention, includes a preheating step using steam to raise the temperature of the applied carpet backing composition, and then leads to main drying using high temperature and hot air to improve drying properties and blister resistance. Improved.

Conventional drying systems without steam preheating, as shown in Figure 2, have poor drying performance.Therefore, attempts are made to dry by increasing the humidity of the dryer, but the blister resistance deteriorates and the main physical properties of the carpet after drying deteriorate. The yarn strength and peel strength are weak.

As described above, the present invention makes it easier to dry a specific carpet backing composition by increasing the temperature of the composition by preheating with steam after applying it to a carpet greige, and by main drying. In other words, the combined effect of the carpet backing composition and drying system achieves the targeted physical properties of the carpet (q).

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples. Incidentally, parts and percentages in the examples are on a superimposed basis unless otherwise specified.

Various test methods in the examples are as follows.

(1) Peel strength Measured according to JIS L-1021 rug test method.

That is, a backing composition with a solid content concentration of 73% was applied to a gray material made by tufting nylon crimped yarn onto a primary base fabric made of polypropylene, and then a 7-ounce jute was crimped as a secondary base (1) and bonded. After drying under the conditions shown in Table 2, the peel strength of the secondary group A was measured.

(2) Initial peel strength A backing composition with a solids concentration of 73% is applied to a gray fabric made by tufting nylon crimped yarn onto a primary base fabric made of polypropylene, and then a 7 oz shoot is crimped as a secondary base fabric. Bonded and dried for 120' under the drying conditions shown in Table 2.
The peel strength at the initial stage [3 minutes (A) and 7 minutes after bonding (B)] when dried with C was measured according to JIS L-1021.

(3) Back yarn strength The handling strength of one pile was measured under the same conditions as in (1) according to JIS L-1021.

(4) Initial yarn strength According to JIS L-1021, the pulling strength of one pile was determined under the same conditions as in (2) [after lamination, 3 minutes (A), 7
minutes later (B)] was measured.

It should be noted that a strong initial peel strength and initial back yarn strength means that it leads to prevention of selvage (generation of defective products).

5) Blister resistance The undried carpet was placed in a hot air dryer at a temperature of 180°C, and blisters that formed during drying were visually observed and judged. Judgment was made on a scale of 1 to 5. 1
@ indicates that no blisters occurred at all, and 5th grade indicates that blisters occurred all over the surface.

(6) Moisture Content Using a wood moisture meter (manufactured by Kerato Co., Ltd., model M-8A), a needle was inserted into the carpet from the secondary base side to measure the moisture content of the carpet. If the moisture content is high, the peel strength at the initial stage of drying is weak, indicating that the drying properties after processing (drying at 120° C. for 20 minutes) are poor, and therefore the peel strength of the product is weak.

(7) Method for measuring toluene-insoluble content After adjusting the copolymer latex sample to pH 8.0 and coagulating the copolymer in the latex with isopropanol,
1 q of solid matter was washed and dried. This solid content is approximately 0.
3] (Total solid molecule fiA> was immersed in 100 d of toluene at room temperature for 20 hours, and then filtered using No. 2 qualitative filter paper. A portion (cd) of the filtrate was accurately collected,
Evaporate to dryness and obtain residual solid content (toluene soluble content)
(Toluene soluble molecule flB) was weighed, and the toluene insoluble content was determined by the following formula.

A-Bx (100/C)
00'C steam was blown onto the backing surface for 30 seconds.

Examples 1 to 6, Comparative Examples 1 to 11 In addition to 100 parts of monomers of various charge compositions shown in Table 1, an emulsifier, a chain transfer agent, and a polymerization initiator, 0.07 part of ascorbic acid, 5A Ferrous acid 0.005 part, sodium ethylenediaminetetraacetate 0.01 part and water 20
0 part was charged into a stainless steel reactor, and the polymerization temperature was 35-6.
Polymerization was carried out by stirring at 0'C for 20 hours, and copolymer latex A-M was prepared (q).Although the polymerization was carried out in bulk, the polymerization conversion rate of the obtained latex was 99.0% or more. The polymerization stability was good except for latex F and (2), and there was almost no coagulum.

Table 1 also shows the polymerization rate and average particle diameter of the copolymer latex labeled 1q. In addition, the average particle diameter is a value measured according to the above-mentioned microscopy method.

Next, the copolymer latex A-
For 1100 parts by weight (solid content), in addition to the formulation shown in Table 2, 0.8 I parts of potassium pyrophosphate, 1.5 ff of polyoxyethylene nonylphenol ether
lffi part and 1.0 part by weight of styrenated phenol, followed by adding heavy calcium carbonate as a filler,
After sufficient dispersion, the viscosity is approximately 30,000 cps (using Brookfield viscometer, BM type N014, 5 ppm).
A carpet backing composition was prepared by adjusting the viscosity with a thickener and water so that the result was measured under the following conditions, and various carpet tests were conducted.

Table 2 shows the results.

As is clear from Tables 1 and 2, in Examples 1 to 6 using the copolymer latex of the present invention, the resulting carpets had good drying properties (low moisture content), blister resistance, peel strength, and Peel strength, back thread strength, and initial back thread strength are also strong.

On the other hand, in Comparative Example 1.2, (a
) When using a copolymerized latex in which the amount of butadiene, which is an aliphatic conjugated diene nail type matrix, is outside the range of the present invention, Comparative Example 3 shows that 2-ethylhexyl acrylate, which is an acrylic ester having an alkyl group, is However, in all cases, the peel strength, initial peel strength, back thread strength, and initial thread removal strength of the carpet backing composition are weak, the blister resistance is poor, and the moisture content of the carpet is high.

Comparative Example 4.5 contains (b) ethylenically unsaturated carboxylic acid monomers, itaconic acid and acrylic acid, in the monomer charging composition outside the scope of the present invention (Comparative Example 4 below the lower limit, Comparative Example 5 below the lower limit). However, the drying properties of the carpet backing composition are poor, and therefore the initial peel strength is low, and the peel strength after processing is also low.

Comparative Example 6.7 has a copolymer latex whose average particle diameter is outside the range of the present invention (Comparative Example 6 is less than the lower limit, and Comparative Example 7 is greater than the upper limit), but the composition for carpet backing is It has poor blister resistance, low peel strength, and high water content.

Comparative Example 8 is a case in which the copolymer latex is within the scope of the present invention, but the inorganic filler calcium carbonate is outside the scope, and the blister resistance is poor, and the peel strength and thread strength are particularly weak. .

Comparative Examples 9 and 10 use the carpet backing composition of the present invention, but because no steam preheating was performed, the blister resistance was poor.

Moreover, the moisture content is high and the drying properties are poor.

Therefore, the peel strength, initial peel strength, back thread strength, and initial suture removal strength are weak.

Comparative Example 11 is a conventional formulation for improving blister resistance that contains organic polysiloquiline, but it is inferior in blister resistance, drying properties, and stability over time of the composition compared to the formulation of the present invention.

Comparative Example 12 is an example in which the toluene insoluble content is less than the range of the present invention, and the peel strength, back thread strength, blister resistance, and drying properties are poor.

Comparative Example 13 is an example in which the amount of filler is less than the range of the present invention,
Poor blister resistance.

[Effects of the Invention] The present invention combines a carpet backing composition with pre-drying using steam, and compared to conventional products, the drying properties and blister resistance are improved, and the peel strength of the resulting carpet is improved. Improved suture removal strength. Therefore, it has become possible to increase the running speed when drying the carpet. In other words, drying properties, blister resistance, peel strength,
A composition and a carpet manufacturing method (steam preheating) with good thread removal strength can be provided.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an outline of an apparatus used in the carpet manufacturing method of the present invention, and FIG. 2 is an explanatory diagram showing an outline of an apparatus used in a conventional manufacturing method. 1... Carpet gray fabric, 2... Compound bath,
3... Backing composition, 4... Secondary base fabric, 5...
・Steam heating machine, 6... hot air dryer, 7... carpet,

Claims (1)

[Claims] (1) (a) Aliphatic conjugated diene monomer, carbon number is 2 or more
Acrylic ester having 10 alkyl groups or/
and one or more monomers selected from methacrylic acid esters having an alkyl group having 6 to 14 carbon atoms 25 to 65
(b) 0.5 to 8 weight % of an ethylenically unsaturated carboxylic acid monomer; and (c) 27 to 74.5 of another monomer copolymerizable with these.
The toluene-insoluble content obtained by emulsion polymerization of 4% by weight
A carpet backing composition consisting of 100 to 750 parts by weight of an inorganic filler per 100 parts by weight of a copolymer latex (solid content) having an average particle size of 700 to 3000 Å and having an average particle size of 0 to 98% by weight is applied to the gray fabric and heated with steam. A method for manufacturing a carpet, which comprises performing main drying in a hot air dryer after preheating.