JPS59182810A - Production of acrylic resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having improved antistatic properties without deteriorating the original characteristics of the acrylic resin, e.g. transparency, etc., by copolymerizing an acrylic monomer consisting essentially of methyl methacrylate with a small amount of a specific sulfonic acid salt. CONSTITUTION:(A) 100pts.wt. acrylic monomer consisting essentially of methyl methacrylate is copolymerized with (B) 0.5-15pts.wt. sulfonic acid salt of formula I (R<1> is 1-18C hydrocarbon; R<2> is H or methyl; X is 2-4C alkylene oxide; n and m are number average values and 0-35; M is alkali metal, ammonium or organic amine base, etc.) or formula II to give the aimed resin.

Description

[Detailed Description of the Invention] Acrylic resin has a reputation for its elegant luster, outstanding transparency and weather resistance, good mechanical properties and workability, and is used in signboards, lighting equipment, covers, nameplates, various decorative items, etc. Widely used. However, since acrylic resin has strong electrostatic properties, it can easily become electrostatically charged due to friction, etc., and dirt and dust may adhere to the surface, spoiling the beautiful appearance, and causing the instrument panel pointers to become misaligned. is causing problems.

In the past, many methods have been proposed for imparting antistatic properties to such acrylic resins, which are easily charged, and can be broadly classified into the following.

1. A method of adding and kneading surfactants, fatty acid esters of polyhydric alcohols, etc.

2. A method of applying a silicone compound, etc. to the surface of a molded product.

3. A method in which a monomer having a hydrophilic group is polymerized into a resin to chemically modify the structure of the resin.

First, the method of adding and kneading a surfactant etc. includes, for example, a method using higher fatty acid monoglyceride (Japanese Patent Application Laid-open No. 112949/1982), a method of adding an alkyl jetanolamine derivative (Japanese Patent Publication No. 53/21023), etc. is proposed. However, these methods have the disadvantage that the antistatic effect is easily lost by washing with water or rubbing because the surfactant etc. are not chemically bonded to the acrylic resin, and they also require a large amount of surfactant etc. When kneaded into resin, it not only impairs the mechanical properties of the resin, but also causes surfactants to bleed onto the resin surface, creating stickiness, which in turn causes dirt and dust to stick to the resin, impairing its appearance. It has shortcomings.

JP-A-50-109944 describes a compound having a sulfonic acid group in an acrylic resin and polio. However, the compounds having a sulfonic acid group described in this publication are only exemplified by benzene sulfonic acid, Yabara [and luenesulfonic acid], and these sulfonic acids are not chemically bonded to the acrylic resin. In addition, due to poor compatibility with acrylic resin, the surface gloss, which is the original characteristic of acrylic resin,
It has the disadvantage of impairing transparency.

Further, as a method of applying a silicon compound to the surface, for example, a method of applying a partial hydrolyzate solution of ethyl silicate to the surface (Japanese Patent Publication No. 31-6533) has been proposed. This surface coating method has an excellent antistatic effect and can be expected to last long, so it has been put into practical use to some extent, but it requires a process of applying and drying the antistatic agent to the final product, which poses a cost problem. However, it also has the disadvantage that the coating film is damaged due to impact, friction, etc., and the antistatic effect is lost.

Further, as a method of chemically modifying the structure of the resin itself, for example, a method of imparting an antistatic effect by copolymerizing an acrylic monomer with polyalkylene glycol monomethacrylate (Japanese Patent Application Laid-Open No. 56-189516) Publication No.)
etc. have been proposed. This method can be expected to prevent leaching by chemically bonding a nonionic monomer to the resin, but it generally has little antistatic effect, and if a large amount of nonionic monomer is introduced, the resin will not be leached out. However, this method has disadvantages in that the chemical properties and heat resistance are reduced, and the properties of the acrylic resin are significantly impaired, and so far, no satisfactory product has been found in this method.

Therefore, in view of this situation, the inventors of the present invention have conducted intensive studies on a method for manufacturing a resin that has excellent permanent antistatic properties without impairing the original appearance characteristics of acrylic resin. The present inventors have discovered that these requirements can be met by copolymerizing a specific sulfonate with a small amount of a special sulfonate.

That is, the present invention provides 100ffi!, an acrylic monomer whose main component is methyl methacrylate-1. part and general formula (however, the hole in the formula represents a hydrocarbon group having 1 to 18 carbon atoms, R
2 represents hydrogen or a methyl group, and X represents a carbon metal, ammonium, an organic amine base, or an organic quaternary ammonium base l) 0.5 to 15 parts by weight of a sulfonate represented by This is a unique method for producing acrylic resin. The present invention will be explained in detail below.

The acrylic monomer mainly composed of methyl methacrylate used in the present invention refers to methyl methacrylate alone or 50% by weight or more, preferably 70% by weight or more of methyl methacrylate and other copolymerizable vinyl monomers. be.

Copolymerizable vinyl monomers include methacrylic acid esters such as ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate,
Acrylic esters such as butyl acrylate and 2-ethylhexyl acrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, acid anhydrides such as maleic anhydride and itaconic anhydride, 2-hydroxy Ethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, monoglycerol acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Hydroxyl group-containing monomers such as tetrahydrofurfuryl methacrylate and monoglycerol methacrylate, nitrogen-containing monomers such as acrylamide, methacrylamide, acrylonide 9yl, methacrylatelyl, diacetone acrylamide, dimethylamine ethyl methacrylate, allyl glycidyl ether, Epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; styrene monomers such as styrene and α-methylstyrene; Examples include crosslinking agents such as dimethacrylate, allyl methacrylate, divinylbenzene, trimethylol, and propane triacrylate. The type and amount of the copolymerizable vinyl monomer can be appropriately selected depending on the properties of the desired antistatic resin.

Furthermore, additives such as heat stabilizers, ultraviolet absorbers, colorants, plasticizers, and various fillers may be mixed with the monomers as necessary, as long as the amount is within the range that achieves the purpose of the present invention. It can be used as

The sulfonate used in the present invention has the following general formula: , an organic amine base, or an organic quaternary ammonium base).Specific examples include the following formula f.
at~(represented by dl.

+-6@ Potash metal. It is necessary that these sulfonic acid salts contain a methyl moiety, preferably 1 to 10 parts by weight. 0
If the content is less than 5 parts, the desired permanent antistatic property cannot be obtained, and if it is contained in excess of 15 parts by weight, the mechanical strength and water resistance of the resulting resin will decrease, resulting in poor practicality. This is not desirable because it causes Water resistance means that the resin composition does not deteriorate in surface gloss, antistatic property, or transparency when it comes into contact with water. 0.5 to 15 M parts of the sulfonate represented by ) or (11) and optional additives as needed are mixed in advance, dissolved, and polymerized.

This polymerization method may be a well-known polymerization method for producing an acrylic resin containing methacrylate-1 as a main component, and is carried out by bulk polymerization, suspension polymerization, or emulsion polymerization in the presence of a radical polymerization initiator.

Azo compounds and organic peroxides are used as radical polymerization initiators, specifically 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2.2-Azohis (2,4-dimethyl, 4-methoxyvaleronitrile), benzoyl peroxide, lauroyl peroxide, and the like.

A redox polymerization initiator that is a combination of an organic peroxide and an amine may also be used. A water-soluble polymerization initiator is used in emulsion polymerization. These include persulfates such as potassium persulfate, sorta persulfate, ammonium persulfate, etc., hydroperoxides such as butyl hydroperoxide, cumene perhydroxide, etc., and hydrogen peroxide.

There are also redox polymerization initiators that involve a combination of these peroxides and reducing substances such as sodium bisulfite and heavy metal salts. The amount of these polymerization initiators used is about 0.001 to 1% by weight based on the total monomers, preferably 0.01 to 1% by weight.
It is about 0.5% by weight. The polymerization temperature varies depending on the concentration of the polymerization initiator, but is about 10 to 150°C, and 30 to 9
0°C is common.

In addition, there is also a method in which the sulfonate is mixed with a partial submerger of monomers (commonly known as Shirabu) containing methyl methacrylate as a main component to continue polymerization.

The methacrylic resin obtained by the method of the present invention has extremely excellent antistatic properties without impairing the resin's original characteristics such as transparency, surface gloss, mechanical properties, weather resistance, and processability. have. Moreover, its antistatic effect hardly changes with washing with water or friction, and also with aging, making it highly practical.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to these examples. Note that parts in the examples indicate parts by weight.

Example 1 100 parts of methyl methacrylate and 1.5 parts of a sulfonate represented by the formula 0% [25] were mixed and dissolved at room temperature, and then 0.5 parts of lauroyl peroxide was added as a polymerization initiator.
2 parts were added. This mixed solution was poured into a polymerization cell consisting of a polyvinyl chloride casket and two glass plates.
Polymerization was carried out by heating at 7℃ for 6 hours and then at 110℃ for 1 hour to obtain 8M
A thick resin plate was obtained. The obtained resin plate was subjected to the following tests. A comparison was made with a general methacrylic resin plate (manufactured by Sumitomo Chemical Co., Ltd., Sumipex'@ooo), and the results are shown in the first column.

(1) 4 Anti-electricity ■ Surface specific resistance: 8 under standard conditions of 23℃ and 50% humidity
After being left for a day, measurements were taken using a Kyokucho insulation meter (manufactured by Toa Denpa Kogyo, model 5M-10E) in the same atmosphere.

@Half-life: Using a static honest meter (manufactured by Shishido Shokai), a voltage of 10 KV was applied in the same atmosphere as in ①, and then the applied voltage was set to zero and the time until the electrostatic voltage was halved was measured.

(2) Transparency Total light transmittance and haze value were measured in accordance with ASTMI-1003.

Table 1 From Table 1, it can be seen that the resin obtained by the method of the present invention has excellent transparency similar to general methacrylic resin plates, and has far superior antistatic properties compared to general methacrylic resin plates. .

In addition, the heat distortion temperature (ASTM-1) of the obtained resin plate was 6
48) is 106℃, tensile strength (ASTM-D
688) was 7501, which did not impair the heat resistance and mechanical properties of general methacrylic resin plates.

Furthermore, the obtained resin plate was subjected to an accelerated weather resistance exposure test at 68°C for 1000 hours using a Sunshine Weathermeter (manufactured by Ska Test Instruments), but even after the test, the surface specific resistance was 8.1
The antistatic effect had an excellent long-lasting effect with almost no change in X L O''Ω and half-life of 2 seconds.

Examples 2 to 8, Comparative Examples 1 to B Three different thickness resin plates were obtained in the same manner as in Example 1, except that the type and amount of the sulfonate were changed as shown in Table 2. The transparency, antistatic property, and mechanical strength of the obtained resin plate were measured by the same method as in Example 1, and the water resistance was measured by the method noted in Table 3, and the results are shown in Table 3.

Table 2 *Sulfonate CH3COO (CH2CH2O) 4012H25@
KO3S-JMC(X)CH2C=CJ12 crystal 3 li ↓N a U 3 d-L; tiU ri ri (Ul
i2Uf12LJ)9υ1i2Uti; ULL2 Example 9 98 parts of methyltutaacrylate and 2 parts of ethyl methacrylate
After adding parts and parts to a round + i flask and dissolving at room temperature,
Azohisisobutyronitrile 0.01 as a polymerization initiator
The mixture was immersed in a 70° C. oil bath and stirred at low speed for about 1 hour to obtain a partial polymer (silk) with a viscosity of 1 void. 2 parts of sodium allyltridecyl sulfosuccinate and 0.7 part of titanium oxide were added to the silica and dissolved, and then 0.1 part of azohisisobutyronitrile was added as a polymerization initiator. This mixed solution was injected into a polymerization cell consisting of a polyvinyl chloride gasket and two glass plates.
Polymerization was carried out by heating at 70° C. for 5 hours and then at 110° C. for 1 hour to obtain a three-layer resin plate.

The obtained resin plate was white in color and had an excellent surface gloss, and the surface resistivity measured in the same manner as in Example 1 was 1.2 X l O''Ω, and the half-life was 2 seconds. It had excellent antistatic properties.

In addition, the heat distortion temperature (ASTM-D64
8) is 102℃, and the breaking strength of the bale (ASTM-D6) is 102℃.
38) was 7051, which did not impair the heat resistance and mechanical properties of general methacrylic resin plates.

Procedural Sleeve IF Letter (Voluntary) February 1980 Japanese Special 1〆 [Director General Kazuo Wakasugi Tol・Jj (Do I Indication 11? 1158 Special 1r1-Application No. 57687)
No. 2 Name of the invention Method for producing acrylic resin; 3 Name subject to amendment Relationship with one case Name of patent applicant Address Column 6 for detailed explanation of the invention in the specification, 5-in-5 Kitahama, Higashi-ku, Osaka , Contents of amendment 1) From line 4 to line 5 of page 7 of the specification, the phrase "methyl methacrylate alone" is changed to "methyl methacrylate alone."

2) “5” from line 5 to line 6 on page 7 of the specification
Insert "," after "0% by weight or more".

3) On page 7, line 7 of the specification, the phrase "vinyl monomer" has been changed to "mixture with vinyl monomer."

4) From line 14 to line 15 on page 8 of the specification, “
``Trimethylol, propane triacrylate'' is changed to ``trimethylol propane triacrylate.''

5) Replace page 10 of the specification with an attached sheet.

6) In the first line of page 11 of the specification, the phrase "R, in formula 1" is corrected to "R in formula 1."

7) “0” from line 5 to line 6 on page 11 of the specification
．． Insert ``1'' after ``5 to 15 jukanbu''.

8) In Mei NJII, page 11, lines 16 to 17, the phrase "general formula" is corrected to "general formula."

9) In the bottom line of the 11th part of the specification Δ-, "Methacrylate-1." is corrected to "Methyl methacrylate."

Zanso L 10) Page 12 of the specification, lines 7 to 9, "2゜2-Asohis(2,4-dimethyl,4-methoxyvaleronitrile) J" is replaced with ``2,2'-Azohis (2,4
-dimethyl-4-methoxyvaleronitrile)".

11) On page 12 of the detailed letter @ line 9, after “F etc.”
” is inserted.

12) "Persulfate hoop" is corrected to "persulfate hoop" from line 14 to line 15 on page 12 of "Akira #I Shino".

13) On page 12 of the specification, lines 16 to 17, the phrase "cume level hydroxide" is corrected to "cumene hydroperoxide."

14) In the second line of page 18 of the specification, the phrase "preferably" is changed to "preferably".

15) The phrase "change over time" on page 13, line 15 of the specification is replaced with "change over time."

that's all

Claims (2)

[Claims] (1) 100 parts by weight of an acrylic monomer whose main component is methyl methacrylate and the general formula (wherein R
1 represents a hydrocarbon group having 1 to 18 carbon atoms, the pore represents a hydrogen or methyl group, and X represents a carbon metal, ammonium, an organic amine base, or an organic quaternary ammonium base). 5 to 15 parts by weight. (2) The composition according to claim 1, wherein in the structural formula represented by general formula (I) or (n), X is an ethylene oxide group and M is an alkali metal.