JPS6084320A - Production of crosslinked vinyl chloride copolymer - Google Patents

Abstract

PURPOSE:To produce the titled copolymer, by forming a solution of a specified vinyl chroride copolymer and an isocyanate compound in an organic solvent and keeping it at 30-150 deg.C after bringing the solution into a state in which the organic solvent is evaporated almost completely. CONSTITUTION:Use is made of a vinyl chloride copolymer comprising about 60- 95wt% vinyl chloride, about 1-30wt% hydroxyl group-containing vinyl monomer [e.g., 2-hydroxyethl (meth)acrylate], and about 0.05-5wt% acrylic tert. amine [e.g., dimethylaminoethyl (meth)acrylate]. Namely, 100pts.wt. above copolymer and about 0.3-30pts.wt. isocyanate compound (e.g., tolylene diisocyanate) are dissolved in an organic solvent, and the resulting solution is applied to a base or the like and, after evaporating the solvent almost completely, it is kept at 30-150 deg.C to effect crosslinking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a crosslinked vinyl chloride copolymer.

Vinyl chloride copolymers containing vinyl chloride and other polymerizable monomers as polymerization components can be used, for example, in paints, adhesives, films,
It is widely used in applications such as fibers, which are often dissolved in solvents.

In order to be suitable for these uses, products with a relatively low degree of polymerization are often used to improve solvent solubility, but since products with a low degree of polymerization have insufficient physical properties, hydroxyl group-containing monodisperses are often made into polymers. It is known that the physical properties of vinyl chloride resins can be improved by crosslinking them with incyanate.

However, in this method, it is practically necessary to add a low-molecular compound such as triethylamine as a catalyst for the crosslinking reaction, and the disadvantage is that these low-molecular catalysts ooze out onto the resin surface over time. I felt that.

The purpose of the present invention is to provide a method for producing a crosslinked vinyl chloride copolymer that does not require the use of the above-mentioned low-molecular-weight catalyst and therefore does not bleed out. A copolymer solution was prepared by dissolving a vinyl chloride copolymer and an inocyanate compound in an organic liquid, and the organic liquid was substantially evaporated. The present invention relates to a method for producing a cross-linked vinyl chloride copolymer, which is characterized in that the system is maintained at a temperature of 30 to 150°C in a male state.

The amount of vinyl chloride that occupies most of the copolymer in wood [Vl] is not particularly limited, but is usually 60 to 95%.

The vinyl chloride copolymer used in the present invention has a hydroxyl group-containing vinyl monoisomer and an acrylic tertiary amine as essential forming units, and among these, the hydroxyl group-containing vinyl polymer component reacts with the isocyanate compound described below. In addition to having 0@ as a reactive group that forms a crosslinked structure, it also exhibits properties unique to hydroxyl groups such as adhesiveness, dyeability, hydrophilicity, compatibility with other resins, and pigment dispersibility. .

Examples of the hydroxyl group-containing vinyl monoisomer include those having the structure j1r as a reaction product of acrylic acid or methacrylic acid and a polyhydric alcohol, and acrylic acid group or methacrylic acid group amides. For example, 2-hydroxyethyl (meth)acrylate (which is 2
- List both hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. The same applies hereafter), 2-
Hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate represented by the following formula CHx = CR-COO+ C■2CH20±, II
(intt integer from 2 to 9, RFi hydrogen or methyl group),
Polyethylene glycol mono(meth) represented by the following formula
Examples include (meth)acrylic acid esters such as acrylate CH2=CR-CO+CHzCHO÷nH (n is an integer from 2 to 6110 CH3, R is hydrogen or methyl group), and 2-hydroxyethyl-27-acryloyloxy 7-crate. Demai,
A specific example of the latter is N-methylol (meth)acrylamide.

These are used alone or in appropriate combinations as constituent units of copolymers, especially 2-hydroxyethyl (meth)
Acrylate, 2-hydroxypropyl (meth)acrylate, and the like are preferably used.

If the use of simple vinyl containing hydroxyl groups is too much, 0J
The solubility of the copolymer in solvents decreases, and the affinity with water becomes too high, which tends to reduce the water resistance that is a characteristic of vinyl chloride resins. If it is too low, crosslinking reactivity deteriorates. Therefore, the weight ratio of the above-mentioned upper polymer is usually 1 to 30% by weight, preferably 2 to 20% by weight.

The acrylic tertiary amine in the present invention refers to a tertiary amine containing an acryloyl group or a methacryloyl group, and specifically refers to (meth)acrylic acid esters such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate. Suitable examples include dimethylacrylamide and dimethylacrylamide.

The tertiary amine functions as a catalyst for the crosslinking reaction between the hydroxyl groups in the copolymer and the added incyanate compound, and also functions to disperse fine powders such as magnetic iron oxide powder well. . If this amount is too large, the speed of the crosslinking reaction between the copolymer and incyanate will be too high, resulting in problems such as a shortened bot life when used as a paint, making it unusable. Since the reaction rate tends to be low and a sufficient crosslinked structure cannot be obtained, V in the copolymer is generally
C0.05-5%, preferably t-t 0.1-2
I respect %.

The vinyl chloride copolymer before crosslinking can be easily obtained by known methods such as solution polymerization and precipitation polymerization. That is, in the case of the i++ person, a mixture of the same weight of methyl isobutyl ketone and toluene is used as a suitable solvent, and after removing the unreacted monocrystalline solid from the solution-like coelectrolyte, It is used as it is as a raw material for a binder, in the latter case n-hexane is used as a suitable solvent, and the copolymer tri is obtained as a fine powder.

The degree of polymerization of the copolymer at this time is determined depending on the purpose of use, but generally a low degree of polymerization, for example 150 to 600, is appropriate for applications such as paints where a large amount of pigment is added and applied thinly. In applications requiring mechanical strength, such as films or fibers, a high degree of polymerization, for example 800 to 1600, is appropriate.

In the present invention, the incyanate compounds used for crosslinking the vinyl chloride copolymer include tolylene diisocyanate, diphenylmethane diisocyanate, dianisidine diisocyanate, tridene diisocyanate, hexamethylene diisocyanate, metaxylylene diisocyanate, and Examples include a reaction product with 421 moles of trimethylol pro-7 trilenecyanocyanate and 3 moles, and this reactant is commercially available, for example, from Shiraki Polyclekun Kogyo Co., Ltd. under the trade name "Coronate".

If too much incyanate compound is used, the final coating film will become brittle, so it is usually used in an amount of Q3 to 30 parts by weight per 100 parts by weight of the copolymer.

In order to obtain a crosslinked vinyl chloride copolymer by the method of the present invention, the chlorinated vinyl copolymer before crosslinking is mixed with a suitable organic liquid such as toluene, methylbutyl ketone, methylbutyl ketone, inglobil alcohol, cyclohesanone,
Dissolve in benzene, acetone, etc. alone or in a mixture of two or more, add pigments, stabilizers, modifiers, etc. as necessary and mix well, then add incyanate at the end of 7 ft/: The organic liquid is evaporated through final steps such as application to a substrate, film formation, and spinning, and then heated to a temperature of 30 to 150°C, preferably 40 to 130°C. It is.

The organic liquid in the copolymer solution 1 above may be evaporated at room temperature or by heating, but if the temperature is too high after the organic liquid has evaporated and dried, the copolymer will decompose and hydrogen chloride will be released. This may cause inconveniences such as detachment.

The method of the present invention is constructed as described above, in which a copolymer solution in which a vinyl chloride-based copolymer and an incyanate compound are dissolved in an organic liquid is prepared, and the organic liquid is substantially evaporated. Since the temperature is maintained at ~150°C, according to the present invention, the acrylic tertiary amine in the copolymer is heated to an appropriate temperature, and the hydroxyl group-containing vinyl monomer component and in It has a catalytic effect that promotes the crosslinking reaction with cyanate compounds, and a vinyl chloride copolymer with high crosslinking density can be easily obtained, and the low molecular weight catalyst does not ooze out over time like in conventional crosslinked copolymers. It is.

The present invention will be explained below with reference to Examples.

Example 1 A mixed solution of methyl isobutylgeton and toluene (weight ratio: 1
:1) After charging 900y and 6y of isobutyl peroxide, the air inside the autoclave was removed. Next, while cooling the autoclave by passing cooling water at 20''C through the jacket of the autoclave, a single-disc mixture consisting of vinyl chloride, 2-hydroxypropyl acrylate and dimethylaminoethyl acrylate was charged with stirring.

Thereafter, hot water was passed through the jacket and heated until the internal temperature reached 32°C to initiate the polymerization reaction, and the temperature of the reaction system thereafter was maintained at 32°C.

After carrying out the above polymerization reaction for 4 hours, the reaction system was cooled again to 20° C., and unreacted vinyl chloride was removed by blowing nitrogen gas from the bottom to obtain a solution-like copolymer. In addition, vinyl chloride, 2
- Preparation of hydrociglovir acrylate and dimethylaminoethyl acrylate @ 860 ml and 78 ml respectively?
It was 4.52.

The obtained copolymer solution was precipitated using n-hexane, washed, and then dried at 50°C for 24 hours to obtain 3902 of a slightly yellow powdered copolymer A.

The resin A has a polymerization degree of 280 and is 78.9% dust vinyl chloride.
The composition was 20.1% of 2-hydroxypropyl acrylate and 1% of dimethylaminoethyl acrylate.

Next, copolymer A was mixed with toluene-methyl isobutyl ketone (
A 15% copolymer solution was prepared by decanting the mixture (weight ratio 1:1), and then an incyanate compound (
0.65 parts of Nippon dζ Recrekun Kogyo Co., Ltd. (Coronate) was added to the vinyl chloride copolymer and stirred until uniform. (Spread a part of it on a smooth glass plate so that the film thickness is 0.1 mm, and heat it for 2 minutes at room temperature.
After leaving it for 4 hours to remove most of the solvent, place it in an air dryer G.
A transparent film was prepared by drying for 24 hours while heating at 50°C, and the gel fraction and heat adhesion of this film were measured.
j 10” (no adhesion).

On the other hand, while maintaining a part of the above solution at 20°C,
By measuring the increase in viscosity of this solution, the speed of the crosslinking reaction in the solution state was measured using a Type B viscosity meter, and the results are shown in Table 1.

The gel fraction is the weight of the vinyl chloride copolymer film obtained as described above after immersing it in a mixed solvent of toluene and methyl isoptyl getone (weight ratio 1:1) at 50°C for one day. It is a value obtained by dividing the number by the weight of the film before dipping (weight %), and serves as a guideline for determining the reaction efficiency of the crosslinking reaction between the copolymer and the incyanate compound.

Heat adhesion is measured by heating the above copolymer film at a temperature of 120°C for 15 minutes and checking whether the magnetic layers adhere to each other when stacked on each other. In the table, ○ indicates no adhesion ( Also, ×V
i Indicates adhesion.

Example 2 Polymerization was carried out in accordance with Example 1 using the same equipment and the same monosomywood as used in Example 1. However, the preparation of the monomer bodies was slightly changed and the polymerization was carried out in n-hexane.

After the polymerization reaction is completed, unreacted vinyl chloride is removed by blowing nitrogen gas from the bottom, and the copolymer is made into a slurry S.
After purification by repeated extraction and filtration and washing with n-hexane, powder Copolymer B was obtained by drying at 50"C for 24 hours. The composition of Copolymer B was as shown in Table 1. .

In the same manner as copolymer B, copolymers C, D and E having the compositions shown in Table 1 were obtained.

Next, copolymer B-E was mixed, a copolymer solution was prepared in the same manner as in Example 1, an incyanate compound was added thereto, a film was prepared, and the gel fraction, heat adhesion, and solution viscosity were determined. The results were as shown in Table 1.

In the Naoki Example, after removing most of the solvent from the incyanate compound-added copolymer solution, the solution was dried in a vacuum dryer for 50 minutes.
A transparent film was created by drying for 24 hours while heating to 0°C, but the heating time after removing most of the solvent was selected depending on the heating temperature and the wind of the tertiary amine in the copolymer. He is generally considered to have two alter egos.

Table 1 Comparative Examples Similar to Example 2, vinyl chloride Kichi 2- with a degree of polymerization of 560
Hydroxyglopylacrylic [binary copolymer with note (
After preparing 2- and droxypropyl acrylate components (20 deuterium acid form) and adding an isocyanate compound, the viscosity and film properties of the solution were measured.

The results showed that the gel fraction was 12%, the heat adhesion was 'F41 standard X', and no increase in viscosity t' of the solution was observed, indicating that almost no crosslinking reaction had occurred.

patent applicant Sekisui Chemical Co., Ltd. Representative: Mototoshi Numa

Claims (1)

[Scope of Claims] L A copolymer solution is prepared by dissolving a vinyl chloride copolymer having a hydroxyl group-containing vinyl single substance and an acrylic tertiary amine as constituent units and an incyanate compound in an organic liquid. A method for producing a crosslinked vinyl chloride copolymer, which comprises maintaining the system 1 at a temperature of 30 to 150° C. in a state where the organic liquid has been substantially evaporated. 2. The manufacturing method according to item 1, wherein the yarn is maintained at a temperature of 40 to 130°C.