JPS5974150A - Method for destaticizing methyl methacrylate resin molding - Google Patents

Abstract

PURPOSE:To impart good antistatic properties, by adding a specified ionic surfactant and an ester compd. to methyl methacrylate monomer or its low polymer and cell custing the mixtue. CONSTITUTION:A sulfonic acid type surfactant containing in the polyoxyalkylene groups indirectly attached to the sulfo groups through an atom group contg. ester linkage, etc. and which has one to two C8-C22 alkyl, alkenyl, alkylaryl, or a quaternary ammonium salt type surfactant of formula I [wherein R<1> is an 8-22C alkyl, alkenyl, etc.; R<2> is R<1>, a 1-3C lower alkyl, etc.; R<3>, R<4> are each a 2-3C hydroxyalkyl, etc.; X<-> is a sulfonate ion such as a group of formula II or III (wherein R is a 1-3C alkyl; R<1> is H, methyl, etc.) or a phosphonate ion of formula IV (wherein R''' is R)] and an ester devived from an 8-22C aliph. carboxylic acid and a 1-4C lower alcohol are added to methyl methacrylate or its low polymer. The mixture is polymerized by cell casting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for preventing static electricity of methyl methacrylate resin moldings, and more specifically, a method for preventing static electricity of methyl methacrylate resin moldings, and more specifically, a method for preventing static electricity from forming methyl methacrylate resin moldings using a specific ionic surfactant and a specific ester compound. It relates to a method of imparting good antistatic properties to the molded article without impairing its surface properties, coloring properties, transparency, etc., by using these in combination.

In general, synthetic polymer materials are highly electrostatically charged, and are prone to various processing troubles, electrostatic shock, dust collection, and other problems during the manufacturing process of molded products and the use stage of molded products. In methyl methacrylate resin molded products, which are characterized by their transparency, dust adhesion on the surface of the products significantly reduces the product value. The strength of the charging property of such methyl methacrylate resin material is similar to that of other hydrophobic synthetic polymer materials, and many attempts have been made to prevent various problems caused by its charging property, but among these, An industrially advantageous way to impart antistatic properties to a hydrophobic polymer material is to add and mix an antistatic agent to the resin material.

Conventionally, as a method for preventing static electricity in methyl methacrylate resin moldings molded by the cell casting method, various surfactants are added to and mixed with methyl methacrylate monomers or their low polymers, and the mixture is injected into cells and polymerized. A method is proposed.

Among these surfactants used externally, some ionic surfactants such as anionic surfactants and cationic surfactants exhibit antistatic properties even when added in relatively small amounts; Since they have drawbacks such as poor compatibility with methyl methacrylate resins and a tendency to become colored during polymerization, many of them are unable to be put to practical use because they significantly impede the properties of their molded products. In addition, compatibility with methyl methacrylate resins can be improved by introducing atomic groups such as ester bonds, ether bonds, and varioquine algylene groups into the molecules of these ionic surfactants. However, as in the case of polyoxyalkylene ether type nonionic surfactants, which are said to have extremely good compatibility, it is necessary to add a considerably large amount to obtain antistatic properties that are practical. In many cases, deterioration of the mechanical properties of the molded product is unavoidable.

On the other hand, other important technical problems have been pointed out in the production of methyl methacrylate resin molded products by the cell casting method. In other words, when methylacrylate monomers or their low polymers are polymerized in cells, the surface properties and workability of the molded product are determined by the degree of adhesion at the interface between the molded product and the cell. It means that it will be done. If the adhesion is too small, the polymer, which has lost its fluidity, will locally peel off at the cell interface as the polymerization progresses, and the polymerization will be completed, resulting in a completely smooth surface 1d of the molded product. On the other hand, if the adhesion is too thick, it will be difficult to remove the molded product from the cell, and in extreme cases, the cell or molded product will be damaged. cause damage to the product. However, although it is known that the degree of adhesion between cells and molded products is greatly affected by the antistatic agent used, the mechanism of action is unknown, and excessive adhesion may cause However, no technology has yet been established to prevent excessive peeling and to control the degree of peeling to an industrially practical level.

Therefore, in the production of methyl methacrylate resin molded products using the cell casting method, it is necessary to prevent excessive density and excessive peeling without reducing the workability when removing the molded products from the cell. There is a strong desire to develop an excellent antistatic method that does not impair the properties of objects.

In view of the actual situation of slanting, the present inventors have conducted extensive research into antistatic methods for methyl methacrylate-1 resin molded products produced by the cell-casting method. If an ester compound is used in combination as an antistatic agent, excellent antistatic properties can be obtained with a relatively small amount of addition, and it will also prevent excessive adhesion between the two cells and the molded product, as well as the problem of (B) cell contact that occurs during polymerization. The present inventors have discovered that peeling can be prevented, but that it often impairs various properties such as transparency, colorability, and surface properties, leading to the completion of the present invention.

That is, the present invention provides the following method for producing a methyl methacrylate resin molded article by the Celgiast method: The present invention relates to a method for preventing static electricity of a methyl methacrylate-1 resin molded product, which is used in combination with an ester compound.

(1) An ionic surfactant selected from the following (A) or (B).

(A) has a polyoxyalkylene group in the molecule, the polyoxyalkylene group is indirectly connected to a sulfonic acid group through an atomic group containing an ester bond, an ether bond, or an alkylene bond, and has a carbon number of 8 ~22 alkyl groups,
Containing 1 to 2 alkenyl groups or alkylaryl groups 3
57-, sulfonic acid type anionic surfactant.

A quaternary ammonium type 4 cationic surfactant represented by the following general formula.

2 4 However, R1 is an alkyl group, an alkenyl group, an alkylaryl group, or an alkyl group or an alkenyl group containing an ether group, an ester group, or an amide group, each of which has 8 to 22 carbon atoms. R2 is the same as R], carbon number 1~
3 lower alkyl group or a hydroxyalkyl group having 2 to 3 carbon atoms. R3 and R4 are a lower pulkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 2 to 3 carbon atoms. XO is a sulfonate ion or a phosphonate ion represented by the following general formula.

■ R303° (R is an alkyl group having 1 to 3 carbon atoms) (Nyl group) (IT) Aliphatic carboxylic acid having 8 to 22 carbon atoms and 1 carbon number
-4 esters with lower alcohols or partial esters with trihydric or higher aliphatic polyhydric alcohols.

Among the ionic surfactants in the present invention, anionic surfactants are represented by the following general formulas 1) to +V), 1
) sulfoacetate, 1]) sulfosuccine-1.
, 1) sulfoalkyl ether, or ]■) α-
Those selected from sulfo fatty acid esters are preferred, and in the case of one sulfosuccinate, diester types are particularly preferred.

') RO(R'0), uCCH2SO3M0
0 0 Qili)
RO(R'O),n(CH2)n503MIV)
RO (R'O),, C-CHR"803M [However, R is an alkyl group, alkenyl group, or alkylaryl group having 8 to 22 carbon atoms. R' is an alkylene group having 2 to 4 carbon atoms. R' is a carbon an alkyl group having an even number of 8 to 18; m is an integer of 3 to 15; n is an integer of 2 to 4; M is an alkali metal] Specific examples of such anionic surfactants include P O
E (10) Nonyl phenyl ether sulfoacetate sodium salt [However, it means 10 moles of POE(io)U polyoxy7 ethylene, the same shall apply hereinafter], POE (6)
instearyl ether sulfoacetate sodium,
salt, POE (8) lauryl ether sulfoacetate potassium salt, di(POE (10) nonylphenyl ether) sulfosuccine-1f) 41um salt, di(POE
(5) lauryl ether) sulfosuccinate sodium salt, di(POE(8)POP (2) nonylphenyl ether) sulfosuccinate sodium salt [however,
POP (2) is polyquine zolo 62 (1.0) oleyl ether sulfosuccinate monoca') rum salt, POE (10)/nylphenyl ether sulfopropyl ether sodium salt, or POE (
5) Intridene ether-α-sulfopalmitate potassium salt, etc.

Among the ionic surfactants used in the present invention, specific examples of cationic surfactants include lauryltrinotylammonium monomethylphenylphosphonate, dilauryldimethylammonium 7methylphenylphosphonate, lauryltrimethylammonium methylsulfonate, lauryldimethylhydroxyethyl Examples include ammonium methylsulfonate, stearyltrimethylammonium monomethylphenylphosphonate, lauroquinoethyltriethylammonium methylsulfonate, lauroyloxyethyltrimethylammonium ethylsulfonate, lauroylaminopropyltrimethylammonium methylphenylphosphonate. Sulfonic acid ion or (/
It is particularly preferable that the phosphonate ion has a moderate molecular weight, and examples thereof include methylsulfonate anion and methylphenylphosphonate anion. 8 to 2 carbon atoms constituting the ester compound used in combination with the agent
Specific examples of the aliphatic monocarboxylic acids (2) include lauric acid, palmitic acid, stearic acid, oleic acid, and mixed fatty acids obtained from various animal and vegetable oils and fats. Similarly, specific examples of lower alcohols having 1 to 4 carbon atoms constituting ester compounds include monohydric lower alcohols such as methanol, ethanol, propatool, and furinol; Specific examples of the alcohol include trihydric alcohols such as glycerin and trimethylolpropane, tetrahydric alcohols such as cyclycerin, yahentaerythritol, hexahydric alcohols such as rubitol and dipentaerythritol, and the like.

Specific examples of ester compounds obtained from these fatty acids and alcohols include monovalent esters such as methyl oleate, methyl stearate, and butyl norumitate, glycerin monoole 1, glycerine distearate, and sorbitan monooleate. , polyhydric alcohol partial esters such as nrubitan tristearate and glycerin monozaflower oil fatty acid ester.

The main feature of the present invention is to use a specific ionic surfactant and a specific ester compound in combination, and the desired purpose can be achieved when both of them are as described above. For example, , monohydric esters with a large molecular weight such as octyl stearate and oleyl laurate obtained from monohydric alcohols with a large number of carbon atoms, or glycerin triolate and pentaerythritol tetraole 1
Complete esters of polyhydric alcohols such as esters, etc. have poor compatibility with methyl methacrylate polymers, resulting in drawbacks such as promoting interfacial separation with cells during polymerization.

When changing the ratio of ionic surfactant and ester compound used together, generally speaking, as the ratio of the former increases, the transparency and colorability of the molded product tend to deteriorate, and conversely, as the ratio of the latter increases, The antistatic properties of the molded product tend to decrease, and the phenomenon of interfacial peeling with the cells tends to occur. The preferred ratio of both is influenced by the type of compound used, but is usually ionic surfactant/ester compound-5/
It is 1 to 1/4 (weight ratio). Further, the amount of both golden words to be used is preferably in the range of 1.5 to 8 parts by weight, and more preferably in the range of 3 to 6 parts by weight, per 100 parts by weight of the methyl methacrylate resin. In carrying out the present invention by the cell casting method, it is more effective to use stainless steel as the material for the lucel. In the present invention, the methyl methacrylate resin is
Examples include methyl methacrylate homopolymers and copolymers containing methyl methacrylate as a substantial main component with other copolymerizable monomers. When carrying out the present invention, other additives such as antioxidants, ultraviolet absorbers, lubricants, dyes and pigments, etc. may be added to the extent that they do not impair the effects of the present invention.
There is no problem in adding.

Next, in order to make the present invention more specific, examples will be given and explained. Add 2 parts by weight of glycerin monooleate and dissolve uniformly in a flask equipped with a thermometer, a stirrer and a nitrogen gas inlet tube, add 05 parts by weight of benzoyl peroxide as a opening agent, and add 60'lc of hot water. 3 in a bath under a nitrogen gas stream
The mixture was stirred for 0 minutes to obtain a syrupy partially polymerized product. This was injected into a stainless steel cell with a thickness of 2 mm, polymerized for 4 hours in a hot water bath at 60'C, and then polymerized for 2 hours in the open at 130'C.
The polymerization was completed by standing for a period of time to obtain a sheet, which was designated as Example 1.

In the same manner, all the additives listed in Table 1 or 2 were used, Examples 2 to 14 and Comparative Examples 1 to 15 (Comparative Example 15)
(blank).

The surface electrical resistance of these sheets was measured, and the transparency, colorability, and surface condition were evaluated. The results were as shown in Table 3 or Table 4.

The measurement method or evaluation criteria are as follows.

...Surface electrical resistance: After the sheet was left in a constant temperature and humidity room at 20'C and 50% RH overnight, it was measured in the same atmosphere using a super insulation resistance meter (Model SM-5E) manufactured by Toa Denpa Kogyo Co., Ltd.

・・Transparency, colorability, surface condition: The sheet was evaluated with the following criteria by visual observation. Cloudiness is observed...Colored Ikuyu: 〇-No coloration is observed△-Very slight coloration is observed.×-Coloration is clearly observed...Surface condition: 〇-No surface abnormality is observed. Δ - Very slight surface abnormality (due to excessive adhesion or excessive peeling) is observed × - Surface abnormality is clearly observed Table 1 (Additive composition of Examples) Table 2 (Comparative examples) Note) In Tables 1 and 2, the numbers in parentheses are parts by weight added to 100 parts by weight of methyl methacrylate monomer. Activators I to X are each the following compounds.

Activator■C9H19-〇-0(C2H40)1oCCH
2SO3Na activator n: C9H1! l Q 0(
C2H40)5CCH2C9H19+0(C2H40)
s C-CH8C):+Na■ Activator■ Iso-C]8H370(C3H60)2 (
C2H-40)8 CCH2SO3 with activator ■Cl2H
250(C2H40)5C-CH2C12H250(C
2H40)5CCH30aNa.

Activator V: C9H+9a-0 (C2H40).

(CH2)... According to the present invention, in which an ester compound is used in combination with the ester compound, it is possible to impart the desired excellent antistatic properties to the molded article with a smaller amount added than when each is used alone. It is clear that good results can be obtained with other properties as well.

Patent applicant: Takemoto Yushi Co., Ltd. Agent: Hiroshi Yama, Patent Attorney

Claims (1)

[Claims]] When producing a methyl methacrylate-Y resin molded product by the cell casting method, the ionic interface in the following (I) is applied to a methyl methacrylate-1 monomer or low polymer. A method for preventing electrification of a methyl methacrylate resin molded product, which comprises containing an activator and an ester compound in (n). (I) An ionic surfactant selected from the following (A,) or (B). (A) has a polyoxyalkylene group in the molecule, the polyoxyalkylene group is indirectly connected to a sulfonic acid group through an atomic group containing an ester bond, an ether bond, or an alkylene bond, and has a carbon number of 8 to A sulfonic acid type anionic surfactant containing 1 to 2 alkyl groups, alkenyl groups, or alkylaryl groups. (B) A quaternary ammonium salt type cationic surfactant represented by the following general formula. 2 4 [However, R1 is an alkyl group, an alkenyl group, an argylaryl group, or an alkyl group or an alkenyl group containing an ether group, an ester group, or an amide group, each having 8 to 22 carbon atoms. R2 is the same as R1, carbon number 1
-3 lower alkyl group or C2-3 hydroxyalkyl group. R3 and R4 are lower alkyl groups having 1 to 3 carbon atoms or hydroxyalkyl groups having 2 to 3 carbon atoms. XO is a sulfonate ion or a phosphonate ion represented by the following general formula. ■ R80a° (However, R is an alkyl group having 1 to 3 carbon atoms) ■ R'-CtoSOP (However, R' is hydrogen, methyl group, ethyl group, or vinyl group) (II) An alkyl group having 8 to 22 carbon atoms An ester of an aliphatic carboxylic acid and a lower alcohol having 1 to 4 carbon atoms or a partial ester of an aliphatic polyhydric alcohol of trihydric or higher valence. 2 The sulfonic acid type anionic surfactant is selected from 1) sulfoacetate), 11) sulfosuccinate, 11) sulfoalkyl ether, or 1v) α-sulfo fatty acid ester 1) RO (R'OL, , CCH2SO3M0)
00
0ill) RO(R'O)m (C
H2) n503Miv) RO(R'O),,C-C
HR"803M [However, R is an alkyl group, alkenyl group, or alkylaryl group having 8 to 22 carbon atoms. R' is an alkylene group having 2 to 4 carbon atoms. R" is an even number alkyl group having 8 to 18 carbon atoms. Base. ? n is an integer from 3 to 15. n is an integer from 2 to 4. M is an alkali metal] 3. The method for preventing static electricity of a methyl methacrylate resin molded product according to claim 1 or 2, wherein the weight ratio of ionic surfactant/ester compound is 5/1 to 1/4. . 4. A method for preventing electrification of a methyl methacrylate resin molded product according to any one of claims 1 to 3, wherein the material of the cells used in the cell casting method is stainless steel.