JPH09136915A - Production of chlorinated syndiotactic polypropylene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a chlorinated polyolefin excellent in solubility in general- purpose solvents, bondability and heat resistance by suspending a syndiotactic polypropylene powder having a specified specific surface area in water or hydrochloric acid and chlorinating the polymer. SOLUTION: A syndiotactic polypropylene powder having a specific surface area of 300-20,000cm<2> /g is suspended in water or hydrochloric acid, and the polymer is chlorinated to obtain a solvent-soluble chlorinated polyolefin. When a powder of a propylene/α-olefin copolymer is chlorinated, it is necessary to use a copolymer having a content of a syndiotactic polypropylene of 55mol% or above. It is desirable that the degree of chlorinatiom is 10-60wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a water-borne chlorinated syndiotactic polypropylene suitable for coatings, inks, adhesives, and other film formation.

[0002]

2. Description of the Related Art Chlorinated polyolefins produced by an aqueous medium method (aqueous medium method) are characterized by non-uniformity of chlorination than those obtained by solvent method chlorination, and the solvent removal required by the solvent method. It is used for molding products and resin modifiers because it requires neither technology nor measures to prevent environmental pollution caused by solvents.

Chlorinated isotactic polypropylene and chlorinated atactic polypropylene have been used as chlorinated polypropylene used for conventional adhesive applications.

Chlorinated polypropylene shows excellent adhesion to a polypropylene substrate at a low chlorination degree, but is inferior in solvent solubility. Conversely, chlorinated polypropylene at a high chlorination degree is excellent in solvent solubility, but it is not suitable as a substrate. On the other hand, it is known that it does not show close contact.

In particular, isotactic polypropylene is known to be extremely difficult to be chlorinated by a water medium method because of its dense crystal structure.

On the other hand, atactic polypropylene does not exhibit adhesion to a polypropylene substrate because the structure of the resin itself is different from that of the polypropylene substrate and it has almost no crystallinity.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a method for producing a water-borne chlorinated polyolefin that can be used for forming a coating film such as paints, inks and adhesives, that is, it is uniformly dissolved in commonly used solvents such as toluene and xylene. It is an object of the present invention to provide a method for producing a water-borne chlorinated polyolefin that is capable of and has good adhesion to a polypropylene substrate.

[0008]

The present applicant has already disclosed a method for producing a solvent-soluble type chlorinated polypropylene relating to a water medium method (JP-A-3-199207).
As a result of diligent study, we have found a method for producing chlorinated polypropylene having excellent solvent solubility and adhesiveness, which could not be obtained by conventional methods, by chlorinating syndiotactic polypropylene by a water medium method.

That is, the present inventor has made earnest studies to develop a chlorinated polypropylene suitable for use as an adhesive, and as a result, a syndiotactic polypropylene powder having a specific surface area of 300 to 20000 cm ² / g or a propylene content of 55 mol%. The syndiotactic polypropylene copolymer above is suspended in water or hydrochloric acid, and chlorine gas is introduced under at least one condition of irradiation with light, generation of a chlorine radical by heating, or addition of a radical generator. It was found that chlorinated polypropylene excellent in heat resistance and adhesive strength can be obtained by converting the compound into a compound, and thus the present invention has been accomplished.

The reaction conditions during chlorination are as follows: Japanese Patent Publication No. 6-271
It is possible to chlorinate by the method shown in No. 31.

The chlorinated resin thus obtained is adhered as a resin having excellent solubility in a general-purpose organic solvent, adhesion suitability, and heat resistance, which is not found in chlorinated polypropylene obtained by the conventional method. It has become possible to apply it to drug use. At the same time, it became possible to manufacture chlorinated polypropylene with significantly better adhesion than chlorinated polypropylene manufactured by the solvent method.

The adhesive composition of the present invention comprises the above-mentioned chlorinated polypropylene as a constituent element, and is used by mixing it with a pigment, a solvent or various additives.

In the present invention, the specific surface area of polypropylene as a raw material is measured by a gas adsorption method (Micromeritex Flow Soap II 2300, manufactured by Shimadzu Corporation).

In the gas adsorption method, the specific surface area of powder is determined from the adsorption amount of gas molecules. Specifically, it is measured by the following operation.

Mixed gas with a constant flow rate (nitrogen: helium =
(3: 7 volume ratio) shows the change in the mixing ratio of the mixed gas before and after passing through the sample cell by the TCD detector (thermal conductivity detector).
And the amount of gas adsorbed is measured.

That is, the mixed gas at a constant flow rate is introduced into the sample cell containing the powder through the primary measurement of the TCD,
To the secondary measurement of. At this time, the sample cell is immersed in liquid nitrogen and cooled, and when a constant flow rate of the mixed gas is passed through the sample cell, nitrogen gas is adsorbed on the powder surface. When liquid nitrogen is removed after reaching the adsorption equilibrium, the powder naturally warms to room temperature, and the adsorbed nitrogen is desorbed. The mixed gas is introduced into the secondary measurement of TCD after passing through the sample cell.
The gas always flows at a constant mixing ratio in the primary measurement, whereas the mixing ratio of the mixed gas flowing during adsorption / desorption changes in the secondary measurement. Therefore, this change was detected by TCD and obtained here. The surface area is calculated from the adsorption amount of nitrogen.

In the chlorination method described in the present invention, both chlorine gas and catalyst are supplied from the outside of the raw material polypropylene particles, so that the chlorination first proceeds from the outside of the particles. Therefore, the specific surface area of the raw material polypropylene is 300 cm
If it is less than ² / g, chlorination cannot proceed to the inside of the polypropylene particles, and it cannot be uniformly dissolved in an organic solvent such as toluene xylene.

For this reason, it is expected that the larger the specific surface area is, the more chlorinated the interior of the polypropylene particles can be. However, when the specific surface area exceeds 20,000 cm ² / g, the reason is unknown, but during the chlorination reaction. It is excluded from the present invention because it has a demerit such that the reaction solution easily foams, the use of an antifoaming agent is obliged, and the workability becomes poor at the time of solid-liquid separation after completion of the reaction. Is.

As described above, chlorination by the water medium method requires a pulverization process of polypropylene particles, but syndiotactic polypropylene is easier to pulverize than isotactic polypropylene and workability is improved. Was done.

The crushing method includes a mechanical method, a scientific pulverization method (a method of dissolving in a solvent and precipitating with a non-solvent, or
Although there are various methods such as a method in which a resin is heat-melted and then suspended or emulsified in water using an emulsifier or the like), it is preferable to perform it according to the properties of the resin used.

The pulverization carried out in the course of the reaction can be effected by any type of apparatus subject to impact or shearing force, such as a wet type or a mechanical type pulverizer such as a ball mill, a homogenizer, a high speed mixer, a spiral pump and the like.

Usually, the pulverization may be carried out only once before the chlorination reaction. However, if the specific surface area of the bottoming raw material is small, the chlorination reaction may become difficult to proceed in the latter stage of the reaction. It is preferable to perform pulverization once or several times.

Next, in terms of mol% of propylene, since the polypropylene component is involved in the adhesion to the polypropylene substrate, in order to exhibit a practically sufficient adhesion strength,
The content of syndiotactic polypropylene in the copolymer of propylene and α-olefin must be 55 mol% or more. Of course, there is no problem with being 100 mol% syndiotactic polypropylene. 5
If it is less than 5 mol%, it does not exhibit adhesion to polypropylene as a base material, so it was excluded from the present invention.

The degree of chlorination is also one of the factors affecting the performance as an adhesive. If the chlorine content is less than 10% by weight, a uniform and clear solution cannot be prepared for a solvent such as toluene or xylene. On the other hand, if the amount is 60% by weight or more, sufficient adhesive force cannot be obtained for the polypropylene substrate.

Unlike the conventional method of dissolving in a solvent and chlorinating, at a low degree of chlorination, the chlorine distribution has a considerable width and is highly non-uniform.

Therefore, in the polypropylene chlorinated by the water medium method, a segment having a polypropylene-like structure which is hardly chlorinated and a segment which is sufficiently chlorinated are mixed. This bipolar structure is the major feature of water-borne chlorinated syndiotactic polypropylene.

That is, the polypropylene-like structural segment exhibits excellent adhesion to the polypropylene substrate, and the sufficiently chlorinated segment exhibits excellent solvent solubility.

A water-based chlorinated polypropylene made from isotactic polypropylene can have the same structure, but at a low chlorine content shown in the present invention, it may be similar to toluene or xylene because the crystallinity is very high. It could not be dissolved in various organic solvents, and satisfactory performance could not be obtained.

Whether or not the adhesive composition is soluble in the solvent is an important factor required for the adhesive, and those unnecessary for the solvent remarkably deteriorate the workability and cannot obtain satisfactory adhesive strength.

The propylene copolymer is ethylene,
And an α-olefin having 4 to 20 carbon atoms. Specifically, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-
Nonene, 1-decene, 1-undecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 4-methyl-1-pentene, 9-methyl-1-decene etc. can be mentioned.

As long as the conditions specified by the present invention are satisfied, any kind of copolymer will have the same excellent effect.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be shown below by examples, but the present invention is not limited to these examples.

[0033]

【Example】

(Example 1) Stirrer, UV irradiation device, with reflux condenser 1
Specific surface area of 700 cm ² / using a 0 L separable flask
A suspension was prepared by using 500 g of syndiotactic polypropylene that had been previously pulverized to be g, using 8 L of ion-exchanged water and a small amount of sodium alkylsulfonate. While irradiating this system with UV, chlorine gas was continuously introduced to chlorinate the chlorine content to 10%. Here, only the chlorinated resin was taken out from the system and the specific surface area was 1500
Re-grinding to cm ² / g and adjusting suspension again for further chlorination to obtain chlorine content of 5% 10% 15% 2
0% 30% 40% 50% 60% 65% 70
When it reached%, it was withdrawn and dried at appropriate times.

(Example 2) Ethylene which had been previously pulverized to a specific surface area of 700 cm ² / g using a 10 L separable flask equipped with a stirrer, a UV irradiation device and a reflux condenser.
A suspension was prepared by using 500 g of syndiotactic propylene copolymer (4 mol% of ethylene component) and 8 L of ion-exchanged water and a small amount of sodium alkylsulfonate. While irradiating this system with UV, chlorine gas was continuously introduced to chlorinate the chlorine content to 10%. Here, only the chlorinated resin was taken out from the system and the specific surface area was 1500
Re-grinding to cm ² / g and adjusting suspension again for further chlorination to obtain chlorine content of 5% 10% 15% 2
0% 30% 40% 50% 60% 65% 70
When it reached%, it was withdrawn and dried at appropriate times.

(Example 3) Using a 10 L separable flask equipped with a stirrer, a UV irradiation device and a reflux condenser, 500 g of isotactic polypropylene previously pulverized to a specific surface area of 3000 cm ² / g was deionized water 8 L. And a small amount of sodium alkyl sulfonate was used to prepare a suspension. While irradiating this system with UV, chlorine gas was continuously introduced to chlorinate the chlorine content to 10%.
Here, only the chlorinated resin was taken out from the system, re-pulverized until the specific surface area reached 10000 cm ² / g, the suspension was readjusted and further chlorinated to give a chlorine content of 5% 10
% 15% 20% 30% 40% 50% 60%
When it reached 65% and 70%, it was taken out and dried at an appropriate time.

(Example 4) Using a 10 L separable flask equipped with a stirrer, a UV irradiation device and a reflux condenser, 500 g of syndiotactic polypropylene previously pulverized to have a specific surface area of 15000 cm ² / g was ion-exchanged water 8
A suspension was prepared using L and a small amount of sodium alkyl sulfonate. While irradiating this system with UV, chlorine gas is continuously introduced to make the chlorine content 5% 10% 1
5% 20% 30% 40% 50% 60% 65
% When it reached 70%, it was timely removed and dried.

COMPARATIVE EXAMPLE 1 Using a 10 L separable flask equipped with a stirrer, a UV irradiation device and a reflux condenser, 500 g of isotactic polypropylene previously pulverized to a specific surface area of 700 cm ² / g was deionized water 8 L. And a small amount of sodium alkyl sulfonate was used to prepare a suspension. While irradiating this system with UV, chlorine gas was continuously introduced to chlorinate the chlorine content to 10%. Here, only the chlorinated resin is taken out from the system, and the specific surface area is
Re-grinding to 1500 cm ² / g and adjusting suspension again for further chlorination and chlorine content 5% 10% 1
5% 20% 30% 40% 50% 60% 65
% When it reached 70%, it was timely removed and dried.

(Comparative Example 2) Ethylene preliminarily ground to a specific surface area of 700 cm ² / g using a 10 L separable flask equipped with a stirrer, a UV irradiation device and a reflux condenser.
Propylene copolymer (ethylene component 4 mol%) 500 g
Was prepared using 8 L of ion-exchanged water and a small amount of sodium alkylsulfonate. While irradiating this system with UV, chlorine gas is continuously introduced to obtain a chlorine content of 1
Chlorinated to 0%. Here, only the chlorinated resin was taken out from the system, re-pulverized until the specific surface area reached 1500 cm ² / g, and the suspension was readjusted for further chlorination so that the chlorine content was 5% 10% 15% 20 % 30% 40
% 50% 60% 65% When 70% was reached, it was withdrawn and dried at appropriate times.

(Comparative Example 3) A specific surface area of 5 was obtained using a 10 L separable flask equipped with a stirrer, UV irradiation device and reflux condenser.
50 cm ² / g syndiotactic polypropylene 50
0 g was dissolved in 8 L carbon tetrachloride. While irradiating this system with UV, chlorine gas is continuously introduced to perform chlorination, and the chlorine content is 5% 10% 15% 20% 30%
When it reached 40% 50% 60% 65% 70%, it was removed by timely and dried.

Using each of the samples obtained in Examples 1 to 4 and Comparative Examples 1 to 3, a 20 wt% toluene solution was prepared and the solubility was evaluated. Among them, the resin having excellent solubility was coated on an OPP film (stretched polypropylene film) using a # 12 Meyer bar, air-dried for one day and then,
A heat seal test was conducted.

In the heat seal test, 13
Width 1 at 0 ° C for 1 second, heat-sealed at ² kg / cm ^2.
It was cut into cm and subjected to a T peel test. Peeling speed is 50 mm /
set to min. Table 1 shows the test results.

[0042]

[Table-1]

[0043]

[Table-2]

[0044]

From the above test results, it can be seen that the heat seal strength is higher than that of syndiotactic polypropylene chlorinated by the solvent method. It is also found that the solvent-solubility and heat-sealing strength are more excellent in balance than the isotactic polypropylene chlorinated by the water medium method.

Although the details of such an excellent effect are not clear, the chlorinated product obtained by the aqueous medium method is not superior to the chlorinated product obtained by the solvent method due to the residual crystal region due to some heterogeneity. It seems to develop solvent solubility and adhesiveness.

Claims (3)

[Claims] 1. A specific surface area of 300 to 20,000 cm ² / g,
The method for producing a solvent-soluble chlorinated polyolefin, which comprises suspending the syndiotactic polypropylene powder as described above in water or hydrochloric acid and chlorinating the powder. 2. A specific surface area of 300 to 20000 cm ² / g,
The content of syndiotactic polypropylene in the copolymer powder of propylene and α-olefin is 5
A method for producing a solvent-soluble chlorinated polyolefin, which comprises suspending 5 mol% or more of the copolymer in water or hydrochloric acid for chlorination. 3. The method for producing a chlorinated polyolefin according to claim 1, wherein the degree of chlorination is 10% by weight to 60% by weight.