JPH01299881A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which is a nonasbestine type, has excellent adhesiveness and coatability and is useful for, e.g., bonding vinyl chloride tiles, by mixing a solution of a vinyl acetate polymer in an organic solvent with a fibrillated polyolefin fiber. CONSTITUTION:A solution if 100 pts.wt. vinyl acetate polymer such as a homopolymer of vinyl acetate or a copolymer of vinyl acetate with an olefin, an unsaturated carboxylic acid or the like in an organic solvent (e.g., methanol) is mixed with, preferably, 2-20 pts.wt. fibrillated fiber of a polyolefin which is a homopolymer of an alpha-olefin or its copolymer with a monomer (e.g., styrene), desirably, fibrillated polyolefin fiber made hydrophilic by spraying with, for example, PVA or modified by copolymerization, desirably, such fibrillated fiber having a freeness of 0.03-8sec/g and a weight-average fiber length of 0.01-2.0mm and, preferably, 100-400 pts.wt. (5-200 pts.wt. per pt.wt. fiber) inorganic filler (e.g., CaCO3) as an optional component and other additives as optional components so that the solid content of the resulting composition may be desirably 60-75wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-asbestos vinyl acetate resin adhesive with improved adhesive strength and coatability.

[Prior Art] Vinyl acetate polymer organic solvent solutions can be used as relatively inexpensive adhesives by blending inorganic fillers with them, for example, for bone-bonding construction of PVC tiles, straight boards, gypsum boards, and wood-wool cement boards. It is used in a wide range of applications, including laminating veneer plywood, polystyrene foam, etc., bonding molds, and bonding air filter elements for automobiles.

However, in this case, asbestos is used as an inorganic filler, but asbestos is designated as a specified chemical substance and has safety and health problems, so asbestos is not used these days. Prescriptions are strongly requested by the industry.

Therefore, various inorganic fillers such as calcium carbonate and clay are being considered as substitutes for asbestos.
Adhesive effect comparable to or better than asbestos,
Coatability was not obtained.

[Means for Solving the Problems] As a result of blood removal studies, the present inventors discovered that vinyl acetate polymer (A
), an adhesive composition containing polyolefin fibril fibers (B), especially polyolefin fibril fibers imparted with wood-philicity, is used as a non-asbestos adhesive with adhesive strength and coating with a combing iron, etc. The present invention was completed based on the discovery that this method can have a remarkable effect on sex.

The adhesive of the present invention not only exhibits good adhesion to PVC tiles, etc., but also has improved thixotropy, allowing smooth coating operations when applied with a trowel, etc., and preventing problems such as sagging on the coating surface. No worries.

In the present invention, the vinyl acetate polymer (A) includes a homopolymer of vinyl acetate, vinyl acetate and ethylene,
Olefins such as propylene, α-octene, α-octadecene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, or their partial or complete esters, anhydrides, nitriles, Copolymers with vinyl amide, vinyl ester such as vinyl propionate, vinyl versatate, vinyl chloride, vinyl ether, etc. may be used. Different types of vinyl acetate polymers can be used together.

The organic solvent is not particularly limited as long as it dissolves the vinyl acetate polymer (A), but methanol, which is industrially available at low cost, is most commonly used, and other solvents such as ethyl acetate,
Common organic solvents such as ethanol, toluene, and acetone are also commonly used in combination with ethanol.

Component (B) of the present invention is polyolefin fibril fiber. Ethylene, propylene, etc. as polyolefins! In addition to homopolymers of α-olefins such as -butene and 4-methyl-1-pentene, monomers copolymerizable with the above α-olefins such as styrene, acrylonitrile,
Examples include copolymers with vinyl chloride, vinyl acetate, acrylic esters, methacrylic esters, block copolymers and graft copolymers thereof.

Advantageously, the polyolefin fibril fibers are rendered hydrophilic. For example, spraying polyvinyl alcohol or its derivatives, starch, cellulose, etc. onto the fibers,
Further, a method of copolymerization modification so that hydrophilic groups such as carboxyl groups and hydroxyl groups are contained in the fiber skeleton is adopted.

The fibers have a water coefficient of 0.03 to 8 seconds/g, preferably 2 to 6 seconds/9, and an average fiber length of 0.01 to 2,0.
m+n preferably 0.01 to 1. A range of 0 mm is used.

The mixing ratio of (A) and (B) is vinyl acetate resin 100%
It is preferred to use 2 to 20 parts by weight, especially 8 to 15 parts by weight, of fibril fibers.

If (B) is less than 2 parts by weight, it is difficult to obtain the effects of the present invention, while if it is more than 20 parts by weight, the system becomes gelled and practicality is reduced.

The adhesive of the present invention may contain other inorganic fillers, other adhesive resins such as rosin and rosin derivatives, fibers, colorants, plasticizers, surfactants, pot life extenders, etc., as necessary. You can. Also, water may be added to the organic solvent in an amount of about 20% or less.

In particular, it is advantageous to use calcium carbonate, clay, talc, titanium oxide, etc. as an inorganic filler.

The filler is used in an amount of about 100 to 400 parts by weight per 100 parts by weight of the vinyl acetate resin, and 5 to 200 times the weight of the refin-based fibril fibers.

The solid content of the adhesive composition is 6.
It is about 0 to 75% by weight.

[Function] The demand for the adhesive composition of the present invention is increasing as it is a non-asbestos type, and because of its excellent adhesive strength and coating properties, it is suitable for adhesive construction of large areas, such as adhesion of rectangular PVC tiles and long tiles. Suitable for use in adhesive construction, etc.

[Example J] Next, the adhesive of the present invention will be further explained with reference to an example. below"
"parts" and "%" are expressed on a weight basis.

Example 1 200 parts of a paste consisting of 100 parts of polyvinyl acetate with a polymerization degree of +000 and 100 parts of methanol were mixed with polyethylene fibril fibers (hydrophilic with polyvinyl alcohol) having a water coefficient of 3 seconds/9, a weight average fiber length of 0, and 8 mm. 200 parts of calcium carbonate and 50 parts of methanol were added to prepare an adhesive.

Using this adhesive, normal adhesive strength, thixoscopic coefficient, and coatability were measured. The results are shown in Table 1.

The measurement method is as follows.

Apply the product to normally adhesive crab birch wood using a comb trowel, press the birch wood with finger pressure, make a test piece with a bonded area of 25 x 25 mm, and after curing at 20°C for 1 day, measure the adhesive force using an autograph at a tensile speed of 20 mm/min. (Measurement atmosphere: 20°C x 65% RH) Thixo coefficient 2 BH type viscometer was used to determine the viscosity ratio at 2 rpm to the viscosity at 2 orpm.Coating property: Apply the adhesive onto the slate board using a standard combing iron according to JIS A3536. and observe the ease of application and the appearance of combs.

Control Examples 1 to 2 Example 1 except that the use of polyethylene fibril fibers was omitted (Control Example 1) and asbestos (Asbestos Tailing manufactured by Nozawa Co., Ltd.) was used in place of the polyethylene fibril fibers (Control Example 2). The same method was followed.

Table 1 shows the results.

Examples 2 to 6 Adhesives shown in Table 1 were prepared according to Example 1 and their properties were investigated. The results are also shown in Table 1.

[Effects] The adhesive of the present invention is a non-asbestos adhesive that exhibits excellent adhesive strength and coatability.

Claims (1)

[Claims] 1. An adhesive composition prepared by blending polyolefin fibril fibers (B) into an organic solvent solution of a vinyl acetate polymer (A). 2. The adhesive composition according to claim 1, which uses polyolefin fibril fibers imparted with hydrophilic properties.