JPS5947754B2 - Carpet with less blister - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carpet using an adhesive with excellent blister resistance, and more specifically, a latex adhesive containing calcium carbonate with a large particle size as a filler is applied to the back side of the carpet. This is a carpet with fewer blisters to apply.

Adhesives are used in the currently widely manufactured tufted carpets to prevent the piles (tufts) that make up the carpets from falling off.

The adhesive also serves to bond the backing, prevent unraveling of the carpet, and provide a desirable texture and dimensional stability.

Conventionally, adhesives used for this purpose are made of polymer latex with fillers, vulcanizing agents, vulcanization accelerators, anti-aging agents, pigments, stabilizers, antifoaming agents, etc. added as necessary, and thickeners. It is an aqueous emulsion formulation whose viscosity is adjusted to the appropriate viscosity for use.

The advantages of using aqueous emulsion formulations are the absence of flame hazards, the low viscosity of the adhesive at high concentrations and ease of processing, the absence of pollution from organic solvents, and the prevention of seepage of the adhesive into the pile. Although this method is suitable, the disadvantage is that it is necessary to evaporate water, which has a large amount of latent heat.

For this reason, in the carpet manufacturing process, large-sized dryers are used to dry carpets at high temperatures and large air volumes in order to increase productivity.

However, if the temperature of the hot air is too high or excessive air volume or speed is applied when drying the adhesive, boiling will occur inside the adhesive, causing some of the adhesive to blow out onto the back of the card. It may damage the product value.

This phenomenon, called blister, is the biggest obstacle to improving productivity in carpet manufacturing processes that use aqueous emulsion formulations as adhesives.

Furthermore, in recent years, most of the base fabric (core) of tufted carpets has been replaced from conventional jute fabrics to polypropylene split yarn woven fabrics.

This polypropylene split yarn base fabric has advantages such as ease of tufting, ability to piece-dye, high strength, and no dimensional change due to water absorption. Blistering is extremely easy to occur due to lack of moisture, and its solution is an important problem that affects carpet productivity.

The present inventors investigated various carpet lining adhesives that are effective in preventing the occurrence of blisters, and found that the particle size of the filler affects the blister resistance.
Passed through a 177 micron standard sieve as described in IS Z8801.

It is effective to use calcium carbonate with an average particle size of 20 to 100 microns, which does not substantially contain particles with a particle size of 177 microns or more, and particularly, calcium carbonate with an average particle size of 40 to 8 microns.
We have found it most preferable to use 0 micron calcium carbonate.

If the average particle diameter is less than 20 microns, many blisters will occur as in the past, and no improvement will be recognized.

Furthermore, although the number of blisters with an average particle diameter of more than 100 microns is reduced, the surface becomes rough, and this phenomenon is particularly noticeable when particles of 177 microns or more are included.

The adhesive having excellent blister resistance in the present invention contains 100 to 700 parts by weight of filler per 100 parts by weight of polymer latex.

If the amount of filler is less than 100 parts by weight, blisters will increase and this is not economically preferable.

Moreover, if it exceeds 700 parts by weight, the adhesive strength will decrease and the commercial value of the carpet will be lost.

Heavy calcium carbonate, which has traditionally been used in carpet adhesives, has an average particle size of 1 to 20 microns, and is obtained by mechanically pulverizing limestone, especially by pulverizing it by dry method. It is something that was given.

The reason why these heavy calcium carbonates are selected is that if the average particle diameter is too small, such as 1 micron or less, it is difficult to disperse them into latex, making it impossible to obtain a highly concentrated adhesive.

Furthermore, when the average particle diameter is as large as 20 microns or more, it has not been used as a carpet adhesive because of the large roughness.

The present inventors have discovered that the blister resistance of the filler is significantly improved when the average particle size of calcium carbonate is increased from 20 to 100 microns.

When conventionally commercially available calcium carbonate having an average particle diameter falling within the range of the present invention was used, very good results were obtained regarding blisters, but roughness was still felt.

In order to overcome this drawback, we used a JIS standard sieve (sieve opening 177 microns) to exclude particles with a particle size of 177 microns or more to a coefficient of 1.0 or less, but in this case there was no roughness and blister resistance. A good calcium carbonate filler was obtained.

The adhesive of the present invention, which is intended to improve blisters, contains the above-mentioned calcium carbonate with an average particle size of 20 to 100 microns and other common fillers such as aluminum hydroxide, clay, curcum, chalk, chalk, and hydrated silica. It can also be used alone or in combination with two or more acids.

Further, the calcium carbonate used in the adhesive of the present invention is made from various naturally occurring limestones or oyster shells, and its main chemical component is carbonate.

Polymer latex applicable to the present invention includes natural rubber latex, SBR latex, self-crosslinking SBR latex, NBR latex, self-crosslinking NBR latex,
It refers to all polymer latexes used for carpet lining, such as polychloroprene latex, ethylene-vinyl acetate copolymer latex, polyvinyl acetate emulsion, and acrylic acid ester emulsion.

Moreover, the carpet manufactured using the adhesive of the present invention refers to all rugs and fabrics whose back side is treated with polymer latex, such as tufted carpets and warp knitted carpets.

Furthermore, the processing methods include a solid coating process (straight backing) that can be finished by simply applying an adhesive to the back side, a process that uses jute woven fabric, synthetic nonwoven fabric, hexagonal gauze, etc. as a backing material to be attached to the back side, and foamed latex. Refers to a carpet manufacturing method using various processing methods, such as latex coating as a pre-coating step.

The carpet of the present invention is particularly advantageous for tufted carpets, which use polypropylene split yarn as the base fabric and are the type most prone to blistering.

The present invention will be explained below with reference to Examples, but the present invention is not limited by the Examples in any way.

Note that all formulations in the examples indicate parts by weight of solid content.

Example 1 100 parts of self-crosslinking SBR latex containing an anti-aging agent and a dispersant were transferred into a beaker equipped with a stirrer, and a small amount of water and 350 parts of various calcium carbonates shown in Table 1 were added as fillers. Add and disperse evenly.

Next, after adding 0.1 part of antifoaming agent ■ to remove air bubbles,
Viscosity 13000 using 1.6 parts of sodium polyacrylate
By adjusting the pressure to 14,000 centipoise, an adhesive with a solid content concentration of 70% was prepared.

■Self-crosslinking SB, R latex: 5L7090 manufactured by Sumitomo Naugatack ■Defoaming agent: Nopco 8034 manufactured by San Nopco Co., Ltd. These adhesive samples were applied to the back side of a carpet greige fabric in which nylon threads were tufted to a polypropylene split yarn base fabric. The coating was applied uniformly at an apparent weight of 140 ogim, and a woven jute backing material was bonded thereon by pressure bonding to obtain an undried carpet.

Table 1 shows the results of measuring the blister index, peel strength of the backing material, and pile yarn pull-out strength for this carpet.
These measurements were performed using the following method.

Blister index: An undried carpet was placed in a dryer at a temperature of 150° C. and a hot air speed of 12 m/sec, and the blisters generated during drying were observed and evaluated according to the following grades.

No occurrence of first-class niblisters was observed.

Grade 3: Small blisters are slightly observed.

Many class 5 niblisters are observed.

More class 7 niblisters are recognized.

A large number of large blisters were observed on the entire surface of the grade 9 carpet.

Peel strength and pile yarn pull-out strength of backing material: After drying the undried carpet at a temperature of 1200C for 20 minutes, JISL
1021-1974//Rug test method.

Both adhesives using calcium carbonate having an average particle size of 2.5 microns and 10.3 microns caused severe blistering.

Compared to this, calcium carbonate with an average particle size of 28.1 microns clearly improves blistering, and calcium carbonate with average particle sizes of 49.0 micron, 65.6 micron, and 80.2 microns causes less blistering. A significant improvement was observed.

Even when calcium carbonate having these various average particle diameters was used, no problems were observed with respect to the peel strength and pile yarn pull-out strength of the backing material, which are important for carpets.

Example 2 The component with a particle size of 177 microns or more is 0.2%,
An adhesive was prepared using calcium carbonate having an average particle size of 65.6 microns, the same self-crosslinking SBR latex as in Example 1, an antifoaming agent, and sodium polyacrylate.

These adhesives were applied to the back side of a tufted carpet gray fabric whose base fabric was polypropylene split yarn and whose pile yarn was acrylic fiber, with an apparent weight of 1200 g/77
An undried carpet was obtained by uniformly applying the mixture at a ratio of +2.

The blister resistance and pile yarn pull-out strength of this carpet were measured using the same method as in Example 1, and the results are shown in Table 2.

Sample No. io had a low solid content concentration and poor blister resistance.

In addition, sample number 11 had good blister resistance, but
The pile yarn pull-out strength is low and cannot be put to practical use.

Compared to these, by adding an appropriate amount of calcium carbonate, satisfactory performance in both blister resistance and pile yarn pull-out strength was obtained.

Example 3 The component with a particle size of 177 microns or more was 0.11%,
An adhesive having the composition shown in Table 3 was prepared using calcium carbonate having an average particle size of 49.0 microns.

Table 3 shows the results of testing these adhesives in the same manner as in Example 1.

Good blister resistance was also observed when natural rubber latex, SBR latex, NBR latex, and mixed latexes thereof were used.

Claims (1)

Claims: 1. A carpet with little blister, characterized in that the main backing adhesive is 100 to 700 parts by weight of calcium carbonate having an average particle diameter of 20 to 100 microns and 100 parts by weight of polymer latex. 2. The carpet according to claim 1, wherein the particle size of calcium carbonate is substantially 177 microns or less. 3. The carpet according to claim 1 or 2, wherein the base fabric is polypropylene and the backing material is jute.