JPS60233139A - Powdery composition - Google Patents

Abstract

PURPOSE:A composition, prepared by blending aluminum hydroxide with polymer powder consisting of vinyl chloride units, vinylidene chloride units and methallyl chloride or allyl chloride units, and having improved melt flowability and anti- blocking property. CONSTITUTION:A powdery composition, prepared by blending 100pts.wt. polymer powder, consisting of vinyl chloride units, vinylidene chloride units and methallyl chloride or allyl chloride units, and having 5-200mu, preferably 5-50mu average particle diameter with 1-20pts.wt., preferably 2-10pts.wt., aluminum hydroxide with 1-50mu, preferably 1-30mu average particle diameter. The polymer powder obtained by suspension polymerization of 4-95wt%, preferably 20-75wt% vinyl chloride, 4-95wt%, preferably 20-75wt% vinylidene chloride and 0.5-20wt%, preferably 2-15wt% (meth)allyl chloride is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder composition particularly useful as a hot melt adhesive.

Vinyl chloride polymers are inexpensive and have excellent flame retardancy, so they are being developed for use in a wide variety of fields.

However, vinyl chloride polymers with high chlorine content inherently have poor melt flowability during heating, and their decomposition temperature and melt flow temperature are extremely close to each other, so their use is limited and their use is limited. It was insufficient to be used as a standard hot-melt adhesive.

Furthermore, when producing nonwoven fabrics or felts from natural fibers or synthetic fibers, it is necessary to give them an elastic feel, and in this case it is necessary to make the particle size as small as possible.

In order to obtain such a fine powder with good melt flowability, a suspension polymerization method was used instead of the conventional emulsion polymerization method, which resulted in poor thermal stability, to produce a copolymer of vinyl chloride and vinylidene chloride. A method is known in which coarse particles of 100 to 200 μm are obtained and then fine powder with an average particle size of 10 to 60 μm is obtained by freeze-pulverization. However, the melt flow temperature and thermal decomposition temperature of the binary copolymer of vinyl chloride and vinylidene chloride are extremely close to each other, and the practical bonding temperature range is narrow. Since this method requires excessive energy and is expensive, it cannot be said to be an industrially advantageous method, and the development of a more advantageous powder composition has been desired.

On the other hand, hot-melt adhesives generally in the form of powder particles, particularly resins with good melt flowability, tend to cause blocking phenomena. Therefore, mechanical pulverization at room temperature becomes difficult, or the storage stability of the obtained product is impaired.

i: chloride, = y, o, ka-1, def It was sufficient.

In view of the drawbacks of the prior art described above, the present inventors.

The present invention was completed as a result of studies on industrially useful powder compositions.

That is, the present invention provides 100 parts by weight of a polymer powder with an average particle size of 5 to 200 μ and an average particle size consisting of vinyl chloride units, vinylidene chloride units, and methallyl chloride or allyl chloride (hereinafter collectively referred to as (meth)allyl chloride) units. It is a powder composition consisting of 1 to 20 parts by weight of aluminum hydroxide having a diameter of 1 to 50 μm.

The powder composition of the present invention has a significantly low melt flow temperature, and the melt flow temperature of the conventionally known chlorine-based polymer is 200°C.
On the other hand, it has excellent blocking resistance, being able to adhere within 2 to 3 minutes at 180°C and showing no blocking property even at 40°C.

゛The proportion of vinyl chloride units in the polymer powder used in the present invention i is preferably 4 to 95% by weight, and as the ratio exceeds 20, the mechanical crushability becomes poor, and when it exceeds 95% by weight, the melt flow temperature becomes high. water.

The proportion of vinyl chloride sumene units is preferably 4 to 95% by weight, more preferably 20 to 750 to 75% by weight.

When the proportion of vinylidene chloride units is less than 4% by weight, the melt flow temperature becomes high, and when it exceeds 95% by weight, the thermal decomposition temperature decreases and the mechanical crushability tends to be poor.

The ratio of (meth)allyl chloride units is 05 to 205
-20% by weight, more preferably 2-15% by weight. (
If the proportion of meta)allyl chloride units is less than 0.5% by weight, the melt flow temperature will be high and the mechanical crushability will tend to be poor, and if it exceeds 20% by weight, the mechanical crushability will be poor. At the same time, the copolymerization rate tends to decrease.

The method for producing the polymer powder in the present invention is not particularly limited, but since polymers obtained by emulsion polymerization tend to have poor thermal stability, it is preferable to employ suspension polymerization.

As the conditions for suspension polymerization, known conditions can be appropriately adopted, but as a special polymerization method, a full-liquid polymerization method in which the gas phase in the polymerization vessel is substantially eliminated (and the polymerization is continued) can also be adopted. Examples are JP-A-56-125411 and JP-A-56-937.
This is specifically disclosed in various publications such as No. 10 and No. 56-118407. It is desirable that the polymerization temperature is 40 to 70°C and the polymerization time is 15 to 3 oHr. As the suspending agent, a copolymer of ethylene oxide and propylene oxide, partially saponified polyvinyl alcohol, methyl cellulose, or a copolymer of vinyl acetate and maleic acid can be used, and as a polymerization catalyst, benzoyl peroxide can be used. , lauroyl peroxide, di-2-ethylhexyl peroxydicarbonate, α,α'-dimethylvaleronitrile, and the like.

Regarding the method of adding monomers to the polymerization system, it is possible to start the reaction by charging each monomer at the same time in the initial stage, but it is possible to start the reaction by charging each monomer at the same time. It is easier to obtain a uniform polymer if these are added in portions in sequence during the polymerization.

In the present invention, in addition to the monomers corresponding to each structural unit of the polymer, that is, vinyl chloride, vinylidene chloride, and (meth)allyl chloride, other monomers may be used in combination. For example, to further reduce the melt flow temperature,
Vinyl esters, vinyl ethers, acrylic esters, or vinyl ketones can be used, and to improve adhesion to highly polar adherends such as metals, acrylic acid, hydroxyethyl acrylate, maleic anhydride, and N-methylacrylamide can be used. , sodium metaallylsulfonate,
Alternatively, monomers such as glycidyl methacrylate can be used. When using these monomers, it is desirable to keep the weight ratio of the total monomers to 10 or less.

The polymer powder used in the present invention can be obtained as a powder with a predetermined average particle size after polymerization by the above-mentioned flood polymerization method, but in general, the average particle size of the polymer powder after polymerization is 50 to 2.
00μ, it can be used as it is, or it can be pulverized by mechanical pulverization means to obtain a powder having a predetermined average particle size.

The average particle size of the polymer powder in the present invention is 5 to 200 microns, preferably 5 to 50 microns.

If the average particle size is less than 5μ, the powder will be too fine to adhere to the adherend, especially if it is applied in a fluid state, and it will easily volatilize, resulting in large losses. It is difficult to adhere to the body, and its peel strength tends to decrease.

The pulverization method can be carried out by providing a mechanical pulverization step using an ordinary commercially available pulverizer. In particular, the polymer of the present invention can be pulverized at around room temperature, thereby avoiding the freezing pulverization method using liquid nitrogen or the like. As a crusher, a ball mill, a colloid mill, a hammer mill, a jet crusher, etc. can be used.

The aluminum hydroxide used in the present invention is Al.

Mockery 0.・It is represented by the chemical formula 3H-O or A/(OH)3, and has an average particle size of 1 to 50μ.

Such particles adhere to the above-mentioned polymer powder particles, and the blocking resistance is efficiently improved. The preferred average particle size of the aluminum hydroxide is 1/100 to 1/1/1 of the polymer powder particle size.
2, and the value is 1 to 50μ.

In addition, the amount of aluminum hydroxide used is 100% of the polymer powder.
The amount is 1 to 20 parts by weight.

When the amount is less than 1 part by weight, there is no effect of imparting blocking resistance and flame retardancy, and when it exceeds 20 parts by weight, the melt flowability is markedly reduced, which is inappropriate. The preferred amount of aluminum hydroxide used is 2 to 10 parts by weight.

Next, the method of mixing polymer fine powder and aluminum hydroxide is as follows.
The general tri-blend method can be used, but when the polymer powder is produced using a suspension polymerization method and is in a slurry state,
It is also possible to add aluminum hydroxide, mix it in an aqueous dispersion state, and then dry it in a centrifugal layer with airflow or/and fluidized fluidization. A uniform powder composition can be obtained by such a method, and a finely divided powder composition can be obtained by using the above-mentioned pulverization method.

The melt flow temperature and thermal decomposition temperature of the powdered composition of the present invention are 150 to 170°C, respectively, as shown in the examples below.
210-220''C.

The powder composition of the present invention has good compatibility between the polymer powder and aluminum hydroxide, has a low melt flow temperature, and has a high thermal decomposition temperature (also has high peel adhesion strength and good blocking resistance, so it adheres well). It can be used as an adhesive or a paint, and is particularly useful as a hot melt adhesive.

EXAMPLES The present invention will be explained in more detail below with reference to Examples and Comparative Examples. The physical properties of the polymer obtained on each side were measured according to the following method.

1. Particle size distribution The proportion (% by weight) of particles having a particle size of 44 μm or more was determined by a wet sieving method. In addition, the average particle diameter was determined using a light transmission type particle size distribution analyzer (manufactured by Moikun Enterprise ■).

2. Melting flow temperature Polymer particles were placed on a smooth steel plate and heated in a thermostat for 3 minutes to reach a temperature at which the particles would melt and the surface would become smooth.

5. Pyrolysis temperature The polymer particles were left in a thermostat for 3 minutes to reach a temperature at which the surface turned black.

4. Peel adhesion strength Spread polymer particles uniformly on a polyester fiber sheet with a thickness of about 1 inch at a rate of 50g/m'', place the same sheet on top of this, and heat at 180℃ x 0.3ky/cdtx for 3 minutes. Peel strength at 25℃ (180℃) after press bonding with
was measured.

5. Blocking resistance temperature: Place the powdered sample in a polyethylene bag and heat it to 0 or 1 k.
A weight was placed on the tube so that the ratio was 1/C11, and the tube was kept in a thermostatic chamber for 2 days at 40'C, and the blocking state was then observed.

Example 1. In a 5i autoclave, 70 parts by weight of vinyl chloride, 26 parts by weight of vinylidene chloride, 4-layer cap of methallyl chloride, GH-23 (partially saponified polyvinyl alcohol with a degree of saponification of 88%) as a suspending agent, Using 1.0 parts by weight of Nippon Gosei Co., Ltd. as one catalyst, 0.5 parts by weight of C2-ethylhexyl peroxydicarbonate and 200 parts by weight of pure water were added, and stirred at 60°C for 20 hours under stirring at 500 rpm. Suspension polymerization was carried out, followed by centrifugal dehydration and drying to obtain a polymer powder.

The polymerization yield was 888 parts by weight. ' This polymer powder was pulverized at room temperature using a bottle mill type pulverizer Hosokawa/Micro ACM-10 Pulperizer (manufactured by Hosokawa Micron ■) using a single pin as a rotor.

To 100 parts by weight of this polymer powder, 6 parts by weight of aluminum hydroxide powder C-301 (trade name made by Sumitomo Aluminum Smelting Co., Ltd.) having an average particle size of 1.0 μm was added and thoroughly mixed to obtain a powdered composition. . Table 1 shows the results of evaluating the physical properties.

1 Examples 2 to 7 and Comparative Examples 1 to 5 Physical properties were evaluated under the same conditions as in Example 1, except that the monomer composition, the amount of aluminum hydroxide used, or the average particle size thereof were changed. The results were as shown in Table 1.

Examples 8 to 9 Using the monomer composition shown in Table 1 and 0.002 part of sodium nitrite as a scale inhibitor, and using the same suspending agent, catalyst, and stirring conditions as in Example 1, the following conditions were met. Liquid polymerization was carried out.

A chamber was provided at the top of a normal 51 polymerization vessel, the polymerization vessel and the chamber were connected with a connecting pipe, and the interior of the polymerization vessel was filled with liquid, and water was injected into the chamber to form a liquid level.

Further, nitrogen gas was pressurized into the gas phase portion of the chamber, and the pressure was made equal to or higher than the vapor pressure due to the rise in polymerization temperature.

20 hours while injecting water into the chamber from the temperature rising completion wave
Suspension polymerization was carried out (details of liquid-filled polymerization are given in JP-A-56-1).
As described in Publication No. 25411).

2 Next, a polymer powder was obtained after dehydration and drying.

The obtained polymer powder was mixed with aluminum hydroxide powder shown in Table 1 in the same manner as in Example 1 to obtain a powder and a composition as described below. .

Table 1 shows the results of evaluating the physical properties of this material.

Claims (1)

[Claims] 1 100 parts by weight of a polymer powder with an average particle size of 5 to 200 μ, consisting of vinyl chloride units, vinylidene chloride units, and methallyl chloride or allyl chloride units, and an average particle size of 1
A powder composition comprising 1 to 20 parts by weight of ~50μ aluminum hydroxide.