JPS63186705A - Production of vinyl polymer - Google Patents

Abstract

PURPOSE:To produce the title polymer having a low residual monomer content and excellent heat resistance, transparency, etc., by polymerizing a vinyl monomer and/or a vinylidene monomer in the presence of a specified polymn. initiator and in the absence of any solvent. CONSTITUTION:0.01-5pts.wt. peroxy ester (e.g., t-butyl maleate hemi-perester) as a polymn. initiator, 0.01-1pt.wt. mercaptan (e.g., lauryl mercaptan), 0.01-1pt.wt. org. amine (e.g., n-octylamine) and 0.001-1pt.wt. organometallic compd. of a metal selected from the group consisting of Sn, Al and Sb (e.g., tin acetylacetonate) are added to 100pts.wt. monomer mixture of 50-100wt.% vinyl monomer and/or vinylidene monomer contg. a polymer or no polymer (e.g., methyl (meth)acrylate) and 50-0wt.% other copolymerizable monomer (e.g., acrylamide). The mixture is polymerized at 50-150 deg.C in the absence of any solvent.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for rapidly polymerizing monomers mainly consisting of vinyl monomers and/or vinylidene monomers using a novel polymerization initiator system. It is related to.

<Prior art> Conventionally, vinyl monomers such as methyl methacrylate and vinylidene monomers having a polymerizable unsaturated bond in the molecule have been polymerized using a radical polymerization initiator, and further polymerization using a redox polymerization initiator has been carried out. Various methods are known.

For example, the benzoyl peroxide/amine combination is a particularly long-known redox polymerization initiator.

In addition, the method described in Japanese Patent Publication No. 41-21037 is
A method of polymerizing methyl methacrylate heptamer with maleic acid hemiperester and an amine at 40 DEG C. or 60 DEG C. for 20 minutes or more is shown to improve discoloration.

In addition, in Japanese Patent Publication No. 45-4630, methyl methacrylate syrup was polymerized at 40°C in the presence of maleic acid hemiperester, a specific basic metal compound such as calcium hydroxide, and a mercaptan, and the curing time was An improved method is presented.

Similarly, Japanese Patent Publication No. 50-22586 describes the polymerization of methyl methacrylate syrup in the presence of a hydrated inorganic filler by the use of maleic acid hemiperester and certain basic metal compounds, water, and mercaptans. In this method, the presence of water is said to particularly promote curing.

Furthermore, in JP-A No. 61-141710, as a method for curing methyl methacrylate in a short time at room temperature, a specific method of curing methyl methacrylate in the presence of a specific metal salt, organic peroxide, organic amine, soluble metal, etc. A polymerization method using an initiator system consisting of a salt has been disclosed.6 <Problems to be Solved by the Invention> However, such conventional redox polymerization initiators are mainly aimed at shortening the polymerization curing time at low temperatures. However, there are practical problems regarding the performance of the polymer obtained by polymerization.

For example, according to British Patent No. 870191, the polymerization and curing rate at low temperatures is increased by combining peroxides such as benzoyl peroxide and lauroyl peroxide with various amines. It is easily deteriorated by light and heat and yellows very easily.

Also, Special Publication No. 41-21037, Special Publication No. 45-4
In the methods of Japanese Patent Publication No. 630 and Japanese Patent Publication No. 50-22586, the aim is to cure in a short time, but in such systems, the curing is carried out in the presence of water or a basic metal compound insoluble in the polymer. This is a polymerization method, and the polymer becomes opaque.

Furthermore, in the method disclosed in JP-A-61-141710, water or a solvent is used to solubilize the metal salt.

Water and solvent remain in such polymers, and they tend to foam due to heating and polymerization heat generation, resulting in a large number of bubbles in the polymers, making them unsuitable as molded products, and also having the disadvantage of lowering the heat deformation resistance temperature. have

As described above, water, solvent, insoluble metal compounds, and even residual monomers remaining in the polymer cause great harm in maintaining and exhibiting the original performance of the polymer.

(Means for solving the problem) That is, the present invention uses monomers mainly consisting of vinyl monomers and/or vinylidene monomers containing or not containing polymers such as peroxyesters (A) and mercaptans. (B
), an amine (C) and at least one organic compound (D) containing a metal selected from tin, aluminum or antimony in the absence of a solvent,
This is a method for producing a vinyl polymer, characterized by polymerizing at 50°C to 150°C.

In the present invention, the vinyl monomer or vinylidene monomer used refers to a monomer having at least one polymerizable unsaturated carbon bond within the molecule; Examples of monomers having polymerizable unsaturated carbon bonds include methyl (meth)acrylate, (meth)
Ethyl acrylate, butyl (meth)acrylate, isopropyl (meth)acrylate, isobornyl (meth)acrylate, bornyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate , phenyl (meth)acrylate, benzyl (meth)acrylate, tribromophenyl (meth)acrylate, furfuryl (meth)acrylate, etc. having 1 to 25 carbon atoms
Acrylic acid esters and methacrylic acid esters with aliphatic alcohol, alicyclic alcohol) Lt, heterooctagalic alcohol, aromatic alcohol or phenol, halogen-containing aromatic ring alcohol or phenol: or styrene, α-methylstyrene Aromatic vinyl compounds such as , p-methylstyrene, p-chlorostyrene, and p-bromstyrene: Vinyl nitriles such as acrylonitrile, methacryloxy group, and crotonitrile Frequently: Vinyl esters such as vinyl acetate: Copper (meth)acrylate ,(
Acrylic acid metal salts and methacrylic acid metal salts such as neodymium meth)acrylate and lead (meth)acrylate Unsaturated carboxylic acids such as niacrylic acid, methacrylic acid, maleic acid, and maleic anhydride; and N-phenylmaleimide,
Examples include imides such as N-cyclohexylmaleimide, 0-tolylmaleimide, N-ethylmaleimide, and N-laurylmaleimide. - I can do it.

The selection of such vinyl monomers or vinylidene monomers
It depends on the performance that the target polymer should have.

For example, optical products such as lenses may be selected depending on required performance such as light transmittance, refractive index, and heat resistance.

From the viewpoint of polymerization curability and transparency, it is preferable to mainly use at least one selected from monomers containing an acryloxy group or methacryloxy group in the molecule, and aromatic vinyl compounds.

Vinyl monomers or vinylidene monomers can also be used in combination or in combination with other copolymerizable monomers.

Other copolymerizable monomers include unsaturated amides such as acrylamide and methacrylamide: 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, diaminoethyl (meth)acrylate, etc. .

Other copolymerizable monomers can be used within a range that does not affect the performance of the polymer, but usually 50% of the total monomers are used.
Use within the range of % by weight or less.

Furthermore, in the present invention, in order to further improve the strength and chemical resistance of the molded article, a polyfunctional monomer having at least two or more polymerizable unsaturated carbon bonds in the molecule can be used.

Such polyfunctional monomers include ethylene glycol (meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, Ethylene glycol or its oligomers, such as tetradeoxyethylene glycol di(meth)acrylate, whose both terminal hydroxyl groups are esterified with acrylic acid or methacrylic acid; neobentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, The hydroxyl groups of other dihydric alcohols such as butanediol di(meth)acrylate are esterified with acrylic acid or methacrylic acid. Esterified with acrylic acid or methacrylic acid; Esterified polyhydric alcohols such as trimethylolpropane and pentaerythritol with acrylic acid or methacrylic acid; and glycidyl acrylate on the terminal hydroxyl group of these dihydric alcohols or polyhydric alcohols. or ring-opening addition of the epoxy group of glycidyl methacrylate; succinic acid,
The epoxy group of glycidyl acrylate or glycidyl methacrylate is ring-opened and added to dibasic acids such as adipic acid, terephthalic acid, phthalic acid, or their halogen-substituted products, or their alkylene oxide adducts; aryl methacrylate, divinylbenzene, etc. Can be mentioned.

Such a polyfunctional monomer can be used together with a monomer having one polymerizable unsaturated carbon bond in the molecule or a copolymerizable monomer, and can be used in the reactive raw material liquid in the present invention. Of these, it can be used in a range of 30% by weight or less.

If it exceeds 30% by weight, it becomes difficult to maintain mechanical strength and transparency, and polymerization tends to become non-uniform, which is not preferable.

Such vinyl monomers used in the present invention and/or
Alternatively, the vinylidene monomer can be used as a monomer, but from the viewpoint of polymerization curability and ease of handling, it can be used as a liquid containing a partial polymerization.

A liquid partially containing a polymer can be prepared by a known method such as dissolving a polymer in a monomer or prepolymerizing a monomer.

The viscosity of the liquid is preferably 10 to 50,000 centivoise for handling reasons.

In the present invention, polymerization can be achieved by using at least one organic compound (D) containing peroxyester (A), mercaptan [(B), amine (C), and a metal selected from tin, aluminum, or antimony. can be done in a short time.

Peroxyester is a peroxide having a peroxyester bond in the molecule, and includes t-butylperoxyacetate, t-butylperoxypivalate, t-butylperoxybenzoate, and t-butylmaleic acid hemiperoxide. Examples include ester, t-butyl fumaric acid hemiper ester, t-7' tylphthalic acid hemiper ester, t-butylsuccinic acid hemiper ester, di-t-butyl fumaric acid hemiper ester.

Among such peroxyesters, it is preferable to use hemiperester, which is a peroxyester having a free carboxylic acid in the molecule.

Peroxyester (A) is used in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the monomers.

If the amount is less than 0.01 parts by weight, the polymerization time becomes practically long, and if the amount exceeds 5 parts by weight, there is little effect in shortening the polymerization time.

Furthermore, the mercaptan IT used in the present invention (
B) refers to a compound having an SH group in the molecule,
lauryl mercaptan, n-octyl mercaptan, α
-Ethylhexylmercaptan, 2-mercaptopropionic acid, glycol dimercaptoacetate, glycol dimercaptopropionate, trimethylolpropane trismercaptoprobionate, and the like.

The mercaptans are added in an amount of 0 to 100 parts by weight of monomers.
．． 01 to 1 part by weight is used.

If the amount is less than 0.01 part by weight, the polymerization time becomes practically long, and even if it is used in an amount exceeding 1 part by weight, there is little effect in shortening the polymerization time.

Furthermore, as the amine (C) used in the present invention, any of -class, secondary, tertiary amines, quaternary ammonium chloride, alkanolamines, etc. can be used. For example, the amines include n-octylamine, lauryl amine, etc. Examples include amine, dibutylamine, tributylamine, N,N-dimethyl-p-toluidine, phenethyldibutylamine, and the like.

The amount of the amine is 0.01 to 100 parts by weight of the monomers.
1 part by weight is used.

When the amount is less than 0.01 part by weight, the polymerization time becomes practically long, and even if it is used in an amount exceeding 1 part by weight, there is little effect in shortening the polymerization time.

The amine used in the present invention may also be used as an inorganic acid such as a hydrochloride.

Among these, amine hydrochloride is preferred because it has the effect of improving mold release properties.

Furthermore, tin, aluminum,
Organic compounds containing metals selected from antimony are
It is soluble in monomers even without the coexistence of solvents such as water and organic solvents, and examples of such metal-containing organic compounds include acetylacetone, phenylacetylacetone, tris (dipivaloyl methanite), and trispiva Allyl compounds of metals such as loyl trifluoroacetonite, organic metal complexes with 2,2.6°6-titramethyl-3,5-hebutadione, and triphenyl compounds.

The organic compound containing the metal is used in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the monomers.

If it is less than 0,001 part by weight, the polymerization time will be practically long, and if it is used in an amount exceeding 1 part by weight, it will not be effective in shortening the polymerization time.

In order to polymerize the monomers of the present invention and those based on an initiator, a conventional polymerization method for polymerizing vinyl monomers can be applied.

Among these, bulk polymerization is suitable as the polymerization method of the present invention, and cast polymerization exhibits its characteristics even in bulk polymerization.

In cast polymerization, after mixing and dissolving the initiator system in the monomers,
It is also possible to inject it into a mold and then raise the temperature to polymerize and harden it.

Since the polymerization initiator system of the present invention has high polymerization activity, it is desirable to carry out the polymerization at the polymerization site as early as possible when mixed with the monomers.

In the initiator system, peroxyester (A) and mercaptans (B) are separately dissolved in monomers, and immediately after mixing the two, they are poured into a heated mold and heated. It can also be cured in a short time in a mold.

In addition, amine (C), organic compound containing metal (D)
may be dissolved in either direction.

The polymerization temperature in the present invention can be in the range of 50 to 150°C, and more preferably polymerization is carried out at 60 to 120°C.
Heat treatment can also be carried out at 50°C.

At temperatures below 50°C, it takes more than 10 minutes for polymerization and curing, and there is a large amount of residual monomer in the polymer, and at temperatures above 150°C, the polymer decomposes due to heat generation and This is not preferable because the amount of residual monomer increases.

Furthermore, pressure can be applied during polymerization and curing within the mold.

This pressure is approximately 1 to 100 kg/-.

According to the method of the present invention, polymerization can be carried out in a short time of 5 minutes or less.

Furthermore, the vinyl monomer and hnylidene monomer used in the present invention may be used in combination with a light stabilizer, a heat stabilizer, an inorganic filler, a coloring agent, a mold release agent, a lubricant, a foaming agent, etc., if necessary.

<Effects of the Invention> According to the present invention, the polymerization time is extremely short, and the resulting polymer has little monomer remaining inside, does not contain water or solvent, has excellent heat resistance and transparency, and has few bubbles. You can get a better product.

In particular, polymers that require transparency can be obtained with excellent heat resistance, light resistance, chemical resistance, strength, etc. in addition to transparency, and can be used for optical parts and the like.

The product obtained by the present invention can also be applied to cast molding and reaction injection molding in which a molded article is polymerized within a mold, can be polymerized in an industrially practical time, and has excellent mold releasability. Therefore, it can be applied to molding large molded products, thin-walled molded products, etc.

Such products include, for example, Fresnel lenses, video projector screens, general purpose lenses, mirrors, optical elements such as optical discs; automotive parts such as sunroofs, windows, grills, lamp covers; washbasins, table tops; , countertops, doors, aquariums,
Examples include building materials such as bathtubs and furniture.

<Examples> The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto.

In addition, the polymerization time in Examples indicates the time at which the polymerization peak temperature was reached after injection into the mold.

The amount of residual monomer contained in the molded article was measured by laser Raman spectroscopy.

The appearance of the molded product was visually observed.

Heat resistance was determined by visual observation of coloring, foaming, etc. after heating the molded product at 150° C. for 30 minutes.

Heat deformation temperature is ASTM D-648, haze value is AS
Measured in accordance with TM D-1003.

Examples 1 to 4 and Comparative Examples 1 to 4 (Production of raw syrup) 21 700 g of methyl methacrylate in a glass flask
and methyl methacrylate resin (Sumipex 8B M
300 g of H1 (manufactured by Sumitomo Chemical Co., Ltd.) was added and stirred and dissolved for 24 hours to obtain a raw syrup.

(Preparation of syrup for casting) Pour 500 g of the above raw syrup into a glass flask, add 5 g of glycol dimercaptoacetate, 0.5 g of trioctylamine hydrochloride, 2.5 g of tin acetylacetone, and then add the mixture as shown in Table 1. A homogeneous syrup was obtained by adding the indicated polymerization initiators and mixing and dissolving them.

(Polymerization mold) Using these syrups, pour into a mold having a space volume of 150 x 150 x 3 mm, seal it, and heat it to 85°C.
was heated to polymerize.

Thirty seconds after the start of heating, the temperature of the liquid in the mold reached approximately 85° C., and the temperature reached a peak due to the reaction heat at the polymerization time shown in Table 1.

After the temperature of the polymer in the mold reached 85° C. again, the mold was immediately opened and the polymer was taken out from the mold.

Table 1 shows the results of measuring the physical properties of the obtained polymer.

Table 1 Examples 5 to 7 and Comparative Examples 5 to 8 Same as Example 1, 1! 450 g of original Shiro Nobu left behind, 25 g of tetraethylene glycol dimethacrylate, 5 g of mono-t-butyl maleic acid hemiperoxyester as a polymerization initiator, and pentaerythritol tetrakis (
5 g of mercaptopropione), 0.5 g of dimethyloctylamine, and 2.5 g of the metal-containing organic compound shown in Table 2 were added and mixed with stirring to obtain a syrup for injection.

After pouring this injection syrup in the same manner as in Example 1,
Cured by polymerization.

The physical properties of the obtained polymerized molded article are shown in Table 2.

It is clear from Table 2 that the molded articles of the present invention have excellent transparency.

Table 2 Examples 8 to 13 and Comparative Example 9 To 500 g of raw syrup produced in the same manner as in Example 1,
As shown in the table, L-butylmaleic acid hemiperoxyester (A), n-o')thyl mercaptan (B)
, dimethyloctylamine (Example 13 only, its hydrochloride) (C), and acetylacetone-tin (D) were added in predetermined amounts, and the white fluff was prepared five times.

Using each of the obtained syrups, polymerization was carried out in the same manner as in Example 1 to obtain molded products.

Table 3 shows the results of measuring the physical properties of the obtained molded product.

\\' Table 3 Example 14 (Preparation of syrup A) To 475 g of raw syrup produced in the same manner as in Example 1, 25 g of neopentyl glycol dimethacrylate was added to 1 mono-t-
10 g of butyl maleic acid hemibaroxy ester, 1.5 g of dimethyldecylamine hydrochloride and 4 g of acetylacetone were added and mixed and dissolved to obtain a uniform syrup A.

(Preparation of syrup B) 10 g of glycol dimercaptoacetate was added to 500 g of the raw syrup prepared in Example 1, and mixed and dissolved to obtain a uniform syrup B.

The resulting syrups A and B did not significantly increase in viscosity even after one day of storage in an atmosphere at 40°C, and were usable.

90 g of syrup A and 890 g of syrup were each fed into a dynamic mixing type mixer with an average residence time of 3 seconds at room temperature using metering pumps with the same discharge volume and mixed at a temperature of 95°C with a diameter of 300 mm and a thickness of 1.2 mm.
It was poured into a mold having the shape of a disc.

After pouring, pressurize the inside of the formwork to 10 kg/cnl,
Polymerization was carried out.

The polymerization peak temperature was reached 2 minutes after the completion of pouring, and the obtained molded product was free of bubbles, sink marks, etc., and had excellent transparency.

The molded product has a haze value of 1.0% and a heat deformation temperature of 92°C.
The residual monomer content was 2%.

Examples 15 to 17 and Comparative Examples 1O to 1) Polymerization molding was carried out in the same manner as in Example 1 at the mold temperatures shown in Table 4.

The respective polymerization times and residual monomers in the molded product were
Shown in the table.

Table 4 In this example, the molded product obtained contained less residual monomer and had excellent heat resistance and transparency.

Examples 18-26 (Preparation of syrup) The monomers shown in Table 5 were placed in a 2Il glass flask, and 0.1g of azobisisobutyronitrile was added and dissolved, then heated to 80°C to polymerize. Ta.

When the viscosity reached approximately 1 void, the polymerization was stopped by cooling to obtain a homogeneous prepolymerized syrup.

(Composition) After mixing and dissolving the post-added monomers shown in Table 5 into the obtained prepolymerized syrup, mono-1-
Butyl maleic acid hemibarokine ester 15g, trimethylolpropane trimercaptoacetate 5g1
5 g of trioctylamine hydrochloride and 5 g of acetylacetone-tin were added and mixed and dissolved to prepare a uniform syrup.

(Polymerization molding and evaluation) Example 1 using each syrup prepared above
A flat plate molded product of 150×150×3 nm was obtained by polymerization in the same manner as above.

The results of measuring the physical properties of the obtained molded products are shown in Table 5. Examples 27 to 29 (Made of 8 rounds of silo rubber) Except for using the monomers shown in Table 6. A preliminary syrup was obtained in the same manner as in Example 18.

(Composition) The same polymerization initiator as in Example 18 was added to the obtained preliminary syrup to obtain a uniform syrup.

(Polymerization molding and evaluation) The same procedure as in Example 18 was carried out.

The results are shown in Table 6.

Table 6

Claims (3)

[Claims] (1) Vinyl monomer with or without polymer and/or
Or monomers mainly consisting of vinylidene monomer,
No solvent is present due to the initiator system consisting of a peroxyester (A), a mercaptan (B), an organic amine (C), and at least one organic compound (D) containing a metal selected from tin, aluminum, or antimony. bottom, 5
A method for producing a vinyl polymer, characterized by polymerizing at 0°C to 150°C. (2) The method according to claim (1), wherein the metal-containing organic compound (D) of the initiator system is an organometallic complex or a metal allyl compound. (3) The initiator system contains 0.01 to 5 parts by weight of peroxyester (A), 0.01 to 1 part by weight of mercaptans (B), and 100 parts by weight of monomers. ) is 0
．． 0.01 to 1 part by weight of the metal-containing organic compound (D), and 0.0001 to 1 part by weight of the metal-containing organic compound (D).