JPS61127711A - Production of acrylic copolymer having vinyl group-containing organosilicon group - Google Patents

Abstract

PURPOSE:To obtain the titled polymer having vulcanizable with hot air at normal temperature because of improved vulcanization characteristics with peroxide, having improved processing properties and physical properties, by copolymerizing radically an acrylic monomer with a specific polymerizable organosilicon monomer. CONSTITUTION:(A) 60-99.99pts.wt. acrylic monomer shown by the formula I (R<1> is H, or methyl; R<2> is 1-8C alkyl, or alkoxy-substituted alkyl) is copolymerized with (B) 0.01-10pts.wt. polymerizable organosilicon monomer [e.g., compound shown by the formula III (Me is methyl), etc.] shown by the formula II (R<3> is polymerizable olefin bond-containing monofunctional organic group; R<4> and R<5> are H, or monofunctional hydrocarbon group; R<6> is monofuncional hydrocarbon, OH, etc.; p is 0-10; q is 0-50; a is 0-2; b is 1-3; a+b=3], and (C) 0-30pts.wt. another ethylenic unsaturated group- containing monomer by the use of a radical polymerization initiator (preferably lauryl peroxide, etc.), to give the aimed polymer.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to a method for producing a new acrylic copolymer into which a vinyl group-containing silicon group is bonded. The object of the present invention is to provide an acrylic copolymer with significantly improved vulcanization properties.

(Conventional technology) Acrylic rubber has traditionally been known as a rubber that has resistance to splashing, bending, and ozone, and is used as a sealing material.

It is widely used in fields such as gaskets and hose materials, taking advantage of its properties such as heat resistance, aging resistance, and oil resistance.

Currently, acrylic rubber has acrylic acid ester as its main component, which is copolymerized with a small amount of active chlorine-containing monomers such as 2-chlorovinyl ether and monochlorovinyl acetate, or epoxy-containing monomers such as glycidyl methacrylate-allyl glycidyl ether. Things are being put into practical use. However, this Keyaki acrylic rubber &C is (a) press-cured for several minutes at a temperature of about 170 to 180°C using a x5g agent such as polyamine or sulfur-soap to complete the vulcanization. Then, vulcanization is required after several hours, and the vulcanization rate is significantly slower than that of other general surface rubbers. →Polyamine vulcanizing agent σ
) are unsuitable for use by medical and food officials due to their safety. There are drawbacks such as.

In order to improve these drawbacks, attempts have been made to introduce unsaturated bonding groups into the side chains. Methods of sulfur vulcanization and t1 peroxide vulcanization are known, but vulcanization is very slow and roll workability is poor, so that no practical product has been obtained.

Recently, a method of copolymerizing an acrylic acid ester and a norbornene derivative and sulfur vulcanization or peroxide vulcanization has been proposed, but although considerable improvements have been made in sulfur vulcanizability, peroxidation In terms of material vulcanization, the vulcanization speed is slow (practical use is difficult).

(Configuration of 5a Akira) The inventors of the present inventors attempted to overcome these conventional drawbacks and completed the present invention as a result of their efforts.

That is, the present invention.

(In the formula, R1 is a hydrogen atom or a methyl group, R1 is an alkyl group having 1 to 8 carbon atoms or an alkyl group substituted with an alkoxy group) 60-99.
99ii parts.

(b) General formula % Formula % (In the formula, R3 is a monovalent 81 group having a polymerizable olefin bond, R4 and 1 are hydrogen atoms or unsubstituted or substituted -valent hydrocarbon groups -R' G1 non-hexasubstituted or a substituted-valent hydrocarbon group, a hydrolyzable group other than a hydrogen atom, a hydroxyl group or a halogen atom, p is 0 to 10, and q is 0 to
5O-a) Engineering 0-2-b is 1-3, a + b = 3
Polymerizable organosilicon 1 represented by a)
Worldly status 0. O1-1011fIi part.

and? -1 Other single casings containing ethylenically unsaturated groups 0 to 30
The present invention relates to a method for producing an acrylic copolymer having a vinyl group-containing organosilicon, which comprises carrying out a copolymerization reaction using a radical polymerization initiator.

The acrylic copolymer that can be removed by the method of the present invention has excessive β? It has significantly superior chemical properties, and has good processability and excellent physical properties.

In particular, regarding the vulcanization characteristics with peroxide, due to the reaction specificity of the vinyl group bonded to the silicon atom, vulcanization proceeds rapidly after an induction period of a few minutes and is completed in a short time.
Normal pressure hot air vulcanization is possible.

It has the advantage of not requiring complicated operations such as post-vulcanization.

The present invention will be explained in detail below.

As described above, the acrylic copolymer obtained by the method of the present invention (1) essentially contains (a) and c-type III polymer component, and optionally copolymerizes (c) m@-mer component. It is characterized by the introduction of a unit bonded with an organosilicon group having a vinyl group directly bonded to a silicon atom. This vinyl group directly bonded to a silicon atom has a reactivity significantly different from that of general vinyl monomers, as disclosed, for example, in Japanese Patent Publication No. 41704/1983.

Even if an organoborinoxane having a vinyl group directly bonded to a silicon atom, a general vinyl 7-1-(olefin monomer), and a σJ mixture are polymerized with a free radical polymerization initiator, the organopolysilokinane will not have a vinyl group. However, only the monovinyl 7mer which causes any undercarriage reaction or grafting reaction undergoes a polymerization reaction, and only a mixture of the polymer obtained by this polymerization and the organopolysiloxane is obtained. As is clear from.

In normal radical polymerization, the vinyl group directly bonded to the silicon atom is preserved as it is.

On the other hand, the unsaturated group bonded to the silicon atom is 3-
(acryloxy)propyl group-3~(methacryloxy)
Propyl group-4-vinylphenyl group, methacryloxymethylene group, etc.

These are easily copolymerized by ordinary radical polymerization in the same way as general ethylenically unsaturated monoruts.

The present invention uses a commonly used radical polymerization initiator to form a mixture consisting of component (a) and a predetermined ratio of e→acid component used as needed.

The desired acrylic copolymer is prepared by conducting a polymerization reaction by a method such as emulsion polymerization, repellent polymerization, solution polymerization, or bulk polymerization. The main component is Bi; the component is an acrylic monomer represented by the general formula +11 above.
One is used: acrylic ester or methacrylic ester.

In the formula, R1 represents a hydrogen atom or a methyl group, and R2 represents an alkyl group having 1 to 8 carbon atoms or an alkyl group substituted with an alkoxy group. Specific examples of R2,7) include a methyl group, an ethyl group, propyl group-n-butyl group,
i-butyl group, pentyl group.

Hexyl group, 2-ethylhexyl group, octyl group.

Examples include methoxyethyl group-ethoxyethyl group. In addition, when the chain length of the ester residue (R2) becomes long, a copolymer with high elasticity can be obtained, while when the chain length of R is short, a copolymer with improved tensile strength, oil resistance, and heat resistance can be obtained. A polymer is obtained.

Next, component (b) is represented by the above general formula, and in formula (b) a polymerizable organic rope body is used. Examples include a cylindrical group, a methacryloxy group, and a 4-vinylphenyl group.

R4 and R5 are a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group.

A phenyl group, an aryl group such as a tolyl group, a cycloalkyl group such as a cyclohexyl group, or a monovalent hydrocarbon group in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, etc. is exemplified. Examples of R6 include hydrogen atoms, hydroxyl groups, O) hydrolyzable groups other than halogen atoms, and unsubstituted or substituted monovalent hydrocarbon groups exemplified by R4 to R5. p,
q, a, and b are equal to the above σJ. (Specific examples of polymerizable organosilicon compounds corresponding to the first component are /xUJ). However, in the following description, Me is a methyl group + Ph is a phenyl group 7
show.

(S-1) ■ Me (S-2) Sauce h (S-4) Me Me Me OMe
Me Me Ms Me I Ph Me! 1-O-C-CH=CH2MeI1-o-ca=aHtMeMe(S-9MeMe0HMe, MeI-0-C-OH=OR.

(S-10) Me Me Me -0-C-CH=CH2 #C in an acrylic polymer By introducing a unit to which the vinyl group-containing organic silicon groups listed above are bonded, vulcanization with an organic peroxide can be performed. The properties have been significantly improved, and atmospheric pressure hot air vulcanization can now proceed easily.

In addition, even when an acidic filler with high sulfur properties is blended, it can be exhibited without being inhibited.

(B) The usage ratio of component (B) is 60 to 99.99.
It is desirable that the amount of component (parts by weight) ranges from 0.0l to 10t11 parts (particularly from 0.1 to s prize parts).

If it is less than 0.01 tt part, the vulcanization rate is slow;
If the amount is more than 1 part, vulcanization will progress too much and the physical properties of the rubber will deteriorate.

Other ethylenically unsaturated group-containing monomers as component e1 are used as necessary.11. hK is styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene, acrylonitrile.

Examples include methacrylonitrile, acrylamide, vinyl acetate, vinyl chloride, vinylidene chloride, ethylene, and polypyrene. When using these monomer components −
(a) l/1 component v for 60 to 99.99 parts by weight of component
It should be no more than 301,111 copies.

If more than 30 parts are used, the original physical properties of the acrylic rubber will be impaired, which is not preferable.

Ammonium monopersulfate is used as a radical polymerization initiator to carry out the copolymerization reaction.

Water-soluble types such as potassium persulfate and hydrogen peroxide.

The half-life of aluminum is 80°C for benzoyl peroxide, lauryl peroxide, azobisinobutyronitrile, peroxydicarbonate, etc.
The following oil-soluble types are preferable - ~ 6 401: When copolymerizing with the following low molecular weights, it is preferable to use a redox catalyst in combination with a reducing agent. For combined use, oil-soluble type is benzoyl peroxide/N.

A combination of N-dimethylaniline is preferred. The preferred polymerization temperature is in the range of 0 to 80°C.

The obtained copolymer can be used as a rubber that has heat resistance, oil resistance, and carp ozone resistance, and can be used in various applications that take advantage of its characteristics, such as sealing materials, gaskets, and hose materials.

Next, specific examples will be given. However, below σ) @ff
In all cases, the term ``part'' simply indicates ``t''.

A closed reactor equipped with a stirrer was used. 200 parts of water and 2 parts of sodium lauryl sulfate were charged and the inside of the reactor was heated to 301:1.
Part 1 M sodium sulfite 0.1 part and sulfur strands 1 iron 0
．． 001 parts VS Added 99 parts of the Queen's monomeric polymer ethyl acrylate (listed above) 1 part was added over 3 hours 6 The inside of the reactor was kept at 30°C for another 1 hour Stirring completes the reaction.

The milky white emulsion obtained by the above emulsion polymerization was
Salting out with OL aqueous solution, washing with water and drying yields a copolymerization product with a yield of 99.5%. Obtained. The Mooney viscosity (ML, +4 (100°C)) of this copolymer was determined and was found to be 51.

On the other hand - The above copolymer was kneaded uniformly with two rolls according to the following formulation (7: Blended with only the stock peroxide), and further kneaded.

℃1/I roll for 30 minutes to remove moisture in the silica, and after cooling, the vaginal peroxide paste was evenly heated.
lly to knead the sheet: :s (compounding recipe) Copolymer 100 parts Finely powdered silica
40 part stearin r! l
1 part zinc oxide
5 parts 50% 2.4-dichlorobenzoyl pero medium side paste 2 parts When this mixed wire sheet was heat-treated at 250°C for 3 minutes in a heat open and vulcanized, a vulcanized rubber sheet was obtained without any foaming. was gotten. About this rubber sheet JI8K
Various physical properties were measured according to 6301. The results were 11 as shown in Table 1.

Table 1 Example 2 230 liters of water was added to a closed reactor equipped with a 4A stirrer.
and Metrose 608) 1-4000 (manufactured by Shin-Etsu Chemical, hydroxyglobil methylcellulose) 0.04
After charging 1 part, the following single temperature compound Butyl acrylate 85.5 parts Acrylonitrile 12.5 parts 5-2 (listed above) 2.0
After adjusting the temperature in the reactor to 45° C., 1.0 part of Perloyl ZPP (diisopropyl peroxydicarbonate manufactured by Nippon Oil & Fat Corporation) was added to initiate polymerization.

The reaction was carried out for 3 hours while maintaining the inside of the reactor at 45°C, and the reaction was further completed by stirring at 50°C for 1 hour. The dried slurry was filtered, dehydrated, and dried to obtain a spherical rubber copolymer having a diameter of 0.5 to 21 m with a yield of 96%. The Mooney viscosity of this product [yL, +, (100°C)] was 55.

Regarding this co-electrical combination, Tomi-on (
The resulting kneaded sheet is uniformly mixed using two rolls.
Press vulcanization was carried out at 70°C for 15 minutes and physical properties were measured. The results are as shown in Table 2 below: 7+:6 (Blend recipe) Copolymer 100 parts FEF carbon black 50 parts Stearin I! 2
1 part zinc oxide 5
Part 65% t-butylcumyl 2 parts Peroxinide paste Table 2 Examples 3 to 8 Copolymerization was carried out in the same manner as in Example 1 by changing the monomer composition (61 as shown in Table 3). The rubber copolymers which had been aged were prepared in Examples 3 to 5. For Examples 6 to 8, kneaded sheets were prepared using the following formulations and vulcanized. Good vulcanized sheets with no foaming were obtained in all cases, and the physical properties of each sheet were +1 as shown in Table 3.

Copolymer 100 parts 100 parts FEF carbon black 50 parts 50 parts Stearic acid
1 part 1 part zinc oxide
5 parts 5 parts Zoyl baroxide paste 2 parts (vulcanization conditions) Examples 3 to 5: The kneaded sheet was press-vulcanized at 17011:×15 minutes.

Examples 6 to 8: The kneaded sheets were vulcanized in hot air at 250CX for 3 minutes at normal pressure.

Comparative examples 1 and 2 Ethyl monoacrylate with the composition shown in Table 4.

Ethylidene norbornene and allyl glycidyl ether were emulsion copolymerized according to Example IVc, and the resulting rubber copolymer was roll-kneaded according to the following formulation.

(Blending recipe) Comparative example 1 Comparative example 2 Copolymer 100 parts 100 parts FgF
Carbon black 50 parts 50 parts Stearic acid 11 parts 1 part Zinc oxide 5 parts 5 parts Dimethyldithiocarba 2N Zinc mate ℃×
When various physical properties were measured for the product vulcanized after 3 hours m+, the following results were obtained as shown in Table 4.

Although the kneaded sheet was vulcanized at 250°C for 3 minutes at normal pressure, only semi-cured sheets with significant foaming were obtained in both Comparative Examples 1 and 2. 2 parts of 50% 2,4-dichlorobenzoyl peroxide paste were used).

Next, the vulcanization curves at 170'C with the formulations of Example 116- and Comparative Example 1゜2 were measured using a JARΦ elastometer type III.
It was as shown in Figure 1.

As is clear from the above results, conventional acrylic rubbers have a slow vulcanization rate, and therefore require a long post-cure Ftv after press vulcanization to obtain desired physical properties. On the other hand, the rubber copolymer produced by the method of the present invention has a fast vulcanization rate, and in particular, the initial release is fast (and the vulcanization is completed in a short time, so Ichinomiya pressure hot air vulcanization is It is possible and σ
] The industrial advantages are enormous.

[Brief explanation of the drawing]

The first diagram shows Example 1.3.6. and comparison I! 1゜2
This figure shows the m-sulfur curve at 170'c for the f+ formulation.

Claims (1)

[Claims] 1. (a) General formula CH_2=C(R^1) (COOR^2) (In the formula, R^1 is a hydrogen atom or a methyl group, and R^2 has a carbon number of 1 to 8. 60 to 99.99 parts by weight of an acrylic monomer represented by an alkyl group or an alkyl group substituted with an alkoxy group. (b) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^3 is a monovalent organic group having a polymerizable olefin bond, R^4 and R^5 are hydrogen atoms or unsubstituted or substituted Monovalent hydrocarbon group, R^6 is an unsubstituted or substituted monovalent hydrocarbon group, a hydrolyzable group other than a hydrogen atom, hydroxyl group or halogen atom, p is 0 to 10, q is 0 to 50, a is 0 0.01 to 10 parts by weight of a polymerizable organosilicon monomer represented by (2, b represents 1 to 3, a+b = 3, respectively), and (c) other ethylenically unsaturated group-containing monomers. body 0-30
1. A method for producing an acrylic copolymer having a vinyl group-containing organosilicon group, which comprises copolymerizing parts by weight using a radical polymerization initiator.