JPH03263404A - Production of liquid polymer - Google Patents

Abstract

PURPOSE:To obtain the title polymer free from problem of odor and capable of providing a cured rubber excellent in water resistance and corrosion resistance to metal when used as compounding agent for rubber by using a specific molecular weight controlling agent when a liquid polymer is produced by radical polymerization. CONSTITUTION:Radical polymerization of raw material monomer is carried out using a hydrocarbon compound selected from (A) a condensed polycyclic hydrocarbon compound consisting of an aromatic ring and aliphatic ring selected from 5-membered ring and 6-membered ring, (B) a single alicyclic hydrocarbon compound consisting of 5-membered ring or 6-membered ring and having two unsaturated double bonds in a ring, (C) an alicyclic hydrocarbon compound consisting of two aliphatic rings selected from 5-membered ring and 6-membered ring and having three unsaturated double bonds in the rings, (D) a compound expressed by formula I (R<1> to R<7> are H or 1-3C alkyl), (E) a compound expressed by formula II (R<8> to R<16> are R<1>), (F) alpha-methylene dimer or styrene dimer and (G) terpinolene, alpha-terpinene, gamma-terpinene or dipentene as a molecular weight controlling agent.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing liquid polymers.

As a modifier and plasticizer for polymer sealant and mixed polymer,
C. It can be used in a wide range of fields.

1-Prior Art] Liquid polymers can usually be produced by methods such as anionic polymerization, emulsion polymerization, which is radical polymerization, and polymer decomposition. Anion small groups are suitable for producing polymers with or without functional groups or polymers with white functional groups at the ends, but methods that introduce various functional groups into the polymer and methods 12 are not preferred. The disadvantage is that the production cost is also high. The method by polymer decomposition is
The drawback is that it is difficult to control the structure and molecular weight of the polymer.

The present invention relates to a method for producing liquid polymers by radical polymerization.It is said that the method by radical polymerization not only allows for the selection of various functional groups, but also allows for relatively easy control of the molecular M. It has its features.

Usually, when a liquid polymer is produced by radical polymerization (C) or emulsion polymerization, a low molecular weight polymer is produced by using a relatively large amount of a molecular weight regulator. In this case, the molecular weight regulator 2 is generally a mercaptan compound,
Sulfur-containing compounds such as G→J sulfur-containing compounds have been used.

[Problems to be Solved by the Invention] When a liquid polymer is produced using a large amount of a sulfur-containing compound as a molecular weight regulator, the sulfur-containing compound remains in the polymer, which causes odor and causes various problems. It can and often does cause problems.

To solve this problem, attempts have been made to remove the residual molecular weight modifier by steam distillation of the polymer solution or polymer emulsion, washing the polymer, or drying the polymer under reduced pressure, but this is not sufficient, and The odor problem became a major issue.

In addition, vulcanized rubber 1, which uses a liquid polymer containing a sulfur-containing compound as a molecular weight regulator as a rubber compounding agent, has the drawback of being inferior in water resistance and metal corrosion resistance. .

1. Means to Solve the Problem] In order to solve the problem described in 1-, various molecular weight modifiers were investigated, and the following (A) to (G) were selected as molecular weight modifiers.
A liquid polymer that can solve the odor problem can be obtained by performing radical polymerization in step 2 using at least one hydrocarbon compound having a molecular weight adjusting function selected from the group of The vulcanized rubber used as a compounding agent uses a sulfur-containing compound as a molecular weight regulator and liquid rubber as a rubber compounding agent, and has superior water resistance and metal corrosion resistance compared to the vulcanized rubber used as a compounding agent. It turned out that there was.

(A) an aromatic ring of at least ]-lower), a 5-membered ring and a 6-membered ring;
A fused polycyclic hydrocarbon compound consisting of at least one alicyclic ring selected from member rings.

(B) A monocyclic alicyclic hydrocarbon compound which is a 5-membered ring or a 6-membered ring and has two unsaturated double bonds in the ring.

(C) An alicyclic hydrocarbon compound consisting of two alicyclic rings selected from a 5-membered ring and a 6-membered ring, and having three unsaturated double bonds in the alicyclic ring.

(I)) - A hydrocarbon compound having the structure represented by Noshiro (1).

4 (E)-A hydrocarbon compound having a structure represented by Noshiro (II).

(R, I to R16 are hydrogen or an alkyl group having ~3 carbon atoms) (F) α-methyl sulfur nondimer or styrene dimer (G) Terpinolene, α-terpinene, γ-rutylpinene or dipentene.

Preferred specific examples of the molecular weight regulator of group (A) of the present invention include 9
．． 10-dihydroanthracene, 1,4 dihydronaphthalene, 1,2-dihydronaphthalene, 1.2,3.4-
Tetrahydronaphthalene, indene.

Preferred specific examples of the molecular weight regulator of group (B) include 1
, 4-cyclohexadiene, 1,4-cyclopentadiene.

Preferred specific examples of the molecular weight regulator of group (C) include 1
, 4,5.8-tetrahydronaphthalene, 2.3-dimethyl-1,4,5,8-tetrahydronaphthalene, 2.
3.6. 7-tetramethyl 1.4,5.8-tetrahydronaphthalene.

Preferred specific examples of the molecular weight regulator of group (D) include 1
, 4-hexadiene, 3-methyl-1°4-hexadiene, 1,4-pentadiene, 3-methyl-1,4-pentadiene, 2,5-hebutadiene.

Preferred specific examples of the molecular weight regulator of group (E) include 3
-Phenyl-1-pentene, 1-phenyl-2-pentene, 1-phenyl-2-hexene, 2-phenyl-3-
Hexene.

can be mentioned.

The amount of the molecular weight regulator of the present invention to be used is not particularly limited as long as the polymer is in a liquid state, that is, the weight average molecular weight is adjusted to about 1,000 to 10,000. , usually used in an amount of 10 to 100 parts by weight. As for the method of addition, it may be added all at once at the start of polymerization, or it may be added in portions during polymerization.

The type of liquid polymer produced in the present invention is not particularly limited as long as it is produced by radical polymerization, but may include butadiene, isoprene, styrene, acrylonitrile,
Examples include homopolymers of monomers such as chloroprene and various acrylic esters, and copolymers of combinations of these monomers. Specifically, butadiene-acrylonitrile copolymer, butadiene-styrene copolymer, polychloroprene, acrylic ester polymer,
Or a copolymer etc. are mentioned.

The polymerization method of the present invention may be any radical polymerization, and examples thereof include emulsion polymerization, solution polymerization, and bulk polymerization. Among these, emulsion polymerization is common. Polymerization is carried out using a radical polymerization initiator such as an organic peroxide in the presence of an emulsifier at a temperature of 0 to 60°C.

This will be explained in detail in Examples below.

[Example] Example 1 The polymerization recipe is as follows (polymerization temperature: 10'C).

Part by weight water 1
00 Butadiene 65 Acrylonitrile 35 Potassium dodecylbenzenesulfonate 6 Ferrous sulfate
0.005 para-menthane hydroperoxide 0.02 potassium phosphate
0.3 turbinolene
25 After starting polymerization using the above recipe, when the conversion rate reached 90%, 0.5 part by weight of sodium dimethyldithiocarbamate was added to stop the polymerization. After removing unreacted monomers by steam distillation, 1 part of 2,6-di-tert-butylcresol was added as a stabilizer, and the latex was poured into a 1% aqueous solution of aluminum sulfate to coagulate the polymer. . After solidification, the polymer was washed with water and vacuum dried at 100°C for 12 hours.

The polymer thus obtained had a weight average molecular weight of 6,
500, the polymer composition was 65% by weight butadiene content and 35% by weight acrylonitrile content.

Note that the bound acrylonitrile content was determined from the nitrogen content by elemental analysis. Moreover, the polystyrene equivalent value obtained by GPC measurement was used for the molecular weight.

Using the obtained liquid polymer, a vulcanizate was prepared according to the following formulation and conditions, and the physical properties were evaluated. The results are summarized in Table-1.

(Distribution 6) Part by weight N B R, 100 (N22O8B Synthetic Rubber Co., Ltd.) Carbon black 50 Liquid polymer 10 Diocdylphthale 1.]O 0 Thearic acid 1-ZnO
5 Sulfur 2 CZ I TT 1 (Vulcanization conditions) 160°C x 20 minutes Water resistance and metal corrosion resistance were evaluated by the following method [
,Ta.

(Water resistance, M'': IIt standard method) Before and after immersing the vulcanized sheet in distilled water at 70°C for 70 hours, the volume change of the vulcanized sheet was determined, and the volume change rate was evaluated. A small force indicates water resistance).

(Blood 1 Metal Corrosion Measurement Method) Vulcanized Sea h G ],, OX 1. It was cut into a size of 0mm.

A 2mm thick copper plate (JIS H3100) is attached to this I-.
Cut it into 3x3cm pieces and use 1°OO mesh abrasive paper.
・After layering, degrease and place a copper plate on the 3D Oml
I put it in a specimen bottle. Place the specimen bottle in 80°C Guy-au-Gine] 1. Leave to stand for 24 hours, then remove the copper plate and evaluate the degree of corrosion by 1. ”I checked it visually. ○ those with no corrosion, × those with corrosion
Displayed in .

Examples 2 to 7, Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 by changing the type and amount of the molecular weight regulator.

Next, using the obtained liquid polymer, a vulcanizate was prepared using the same formulation as in Example 1 except that the type of liquid polymer was changed, and the physical properties were evaluated. The results are summarized in Table-1.

As can be seen from Table 1, no particular odor was observed when the hydrocarbon molecular weight modifier of the present invention was used. On the other hand, when a mercaptan-based molecular weight regulator was used, a characteristic odor was observed. When manufacturing ordinary high molecular weight polymers, a small amount of molecular weight regulator is sufficient.
There is little residual molecular weight modifier, and the effect of mercaptan on odor is small, but since a large amount of molecular weight modifier is used when producing low molecular weight polymers, the effect of mercaptan-based molecular weight modifier on odor is large. This is 17. hand,
The effects of the hydrocarbon molecular weight regulator of the present invention are remarkable.

In addition, compared to vulcanized rubber using a liquid polymer containing a sulfur-containing molecular weight modifier as a compounding agent, the vulcanizate compounded using the liquid polymer of the present invention has no odor, and has excellent water resistance and metal corrosion resistance. It is clear that it is superior to

2 The following margins [Effects of the Invention] 1. Using the hydrocarbon yarn/molecule h1'' regulator of the present invention, it becomes a 1'' amount regulator, and 2. the problem of odor caused when using a sulfur compound. resolved. In addition, compared to commonly used mercaptan compounds, the molecular weight modifier of the present invention has low solubility in water, so it does not remain in the water.
ffi ; IA moderator is less likely to be extracted by water and has superior water resistance. Furthermore, sulfur compounds have the property of corroding metals, but the molecular weight modifier of the present invention is hydrocarbon-based and has excellent metal corrosion resistance.

Claims (1)

[Claims] (1) When producing liquid polymer by radical polymerization,
A method for producing a liquid polymer, characterized in that a hydrocarbon compound having a molecular weight regulating function of at least one kind selected from the following groups (A) to (G) is used as a molecular weight regulating agent. (A) A fused polycyclic hydrocarbon compound consisting of at least one aromatic ring and at least one alicyclic ring selected from a 5-membered ring and a 6-membered ring. (B) A monocyclic alicyclic hydrocarbon compound that is a 5-membered ring or a 6-membered ring and has two unsaturated double bonds in the ring. (C) An alicyclic hydrocarbon compound consisting of two alicyclic rings selected from a 5-membered ring and a 6-membered ring, and having three unsaturated double bonds in the alicyclic ring. (D) A hydrocarbon compound having a structure represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (E) A hydrocarbon compound having a structure represented by general formula (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (R^1 to R^1^6 are hydrogen or alkyl groups having 1 to 3 carbon atoms) (F) α-methylstyrene dimer or styrene dimer. (G) Terpinelene, α-terpinene, γ-terpinene, or dipentene.