JPH064722B2 - Cold and heat resistant plasticizer for butadiene rubber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cold and heat resistant plasticizer for butadiene rubber. More specifically, it not only aims to improve cold resistance,
The present invention relates to a cold and heat resistant plasticizer for butadiene rubber, which is characterized by heat resistance, particularly low volatility.

[Conventional technology and problems]

In recent years, rubber products have been desired to have improved cold resistance and heat resistance more than ever, with the increase of applications and expansion of use range. Therefore, these improvement measures are very positively taken, and improvement by blending rubbers and improvement by addition of a third component are being considered, and considerable results have been obtained, but either method There are advantages and disadvantages in
No definitive method has been found.

For example, natural rubber (hereinafter abbreviated as NR) and polybutadiene rubber (hereinafter abbreviated as BR), which are considered to have relatively good cold resistance, are used for acrylonitrile-butadiene rubber (hereinafter NBR), which has poor cold resistance.
There is a method to improve the cold resistance of NBR and CR by blending it with chloroprene rubber (hereinafter abbreviated as CR), but in order to improve cold resistance sufficiently, blend a large amount of NR and BR. Since there is also a problem with the compatibility between rubbers, the physical and chemical properties of NBR and CR are often impaired.

In addition, as the addition of the third component, dioctyl sebacate (hereinafter abbreviated as DOS), diisobutyl adipate (hereinafter abbreviated as DIBA), etc. to NR and styrene-butanediene rubber (hereinafter abbreviated as SBR), Dibutyl sebacate, DOS, etc. are well known for CR, NBR, etc., but although they have improved cold resistance, they show extremely poor heat resistance. There are various types of polyester plasticizers, and they have improved heat resistance.
Poor cold resistance. This tendency also applies to trimellitic acid ester-based plasticizers and pyromellitic acid ester-based plasticizers, and plasticizers excellent in both cold resistance and heat resistance have not been known.

[Means for solving problems]

Therefore, the inventors of the present invention have conducted extensive studies in order to develop a plasticizer that improves cold resistance and heat resistance and other physical properties of rubber, and as a result, found that an ester derived from a specific glycol component and a specific fatty acid component was As a result, they have found that they can improve both cold resistance and heat resistance, and have reached the present invention.

That is, the present invention provides a polyoxyalkylene glycol having a molecular weight of 200 to 5,000 and an alkylene group having 2 to 3 carbon atoms and an unsaturated fatty acid having 14 to 22 carbon atoms and / or a saturated fatty acid having 2 to 24 carbon atoms. A diester having a molecular weight of 600 to 6,000 obtained by the reaction, a polyoxyalkylene glycol having a molecular weight of 200 to 5,000 and an alkylene group having 2 to 3 carbon atoms, and an unsaturated fatty acid having 14 to 22 carbon atoms and / or 2 carbon atoms Cold resistance for butadiene rubber consisting of one or more selected from polyesters having a molecular weight of 600 to 6,000 obtained by reacting a saturated fatty acid having 24 to 24 with a nodicarboxylic acid having 2 to 10 carbon atoms and / or a polymer acid. A heat resistant plasticizer is provided.

Examples of the polyoxyalkylene glycol having an alkylene group having 2 to 3 carbon atoms used in the present invention include polyethylene glycol, polypropylene glycol, and random or block copolymers of ethylene oxide and propylene oxide. The molecular weight of these polyoxyalkylene glycols is required to be 200 to 5,000, and those having a molecular weight of 500 to 2,000 are particularly preferable because they have excellent cold resistance and heat resistance.

In the present invention, since polyoxyalkylene glycol alone has a strong polarity, there is a problem in compatibility with rubber, and esterification with a fatty acid component was carried out to improve this.

Among the fatty acid components used in the present invention, examples of unsaturated fatty acids having 14 to 22 carbon atoms include myristoleic acid, palmitoleic acid, oleic acid, erucic acid, linoleic acid and linolenic acid. Examples of the saturated fatty acid having 2 to 24 carbon atoms include acetic acid, butyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid and behenic acid.

The dicarboxylic acid having 2 to 10 carbon atoms includes, for example, oxalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and the like.
Examples of unsaturated fatty acids of up to 22 are dimerized or more.

The ester according to the present invention can be obtained by esterifying the glycol component and the fatty acid component by a generally known esterification method. The molecular weight of the resulting ester is in the range 600-6000, preferably in the range 600-2500.

The blending ratio of the cold and heat resistant plasticizer comprising an ester compound selected from the above items of the present invention is 100% butadiene rubber.
It is 5 to 60 parts by weight, preferably 10 to 40 parts by weight, based on parts by weight. If the amount is less than 5 parts by weight, sufficient cold resistance cannot be expected, and if the amount is more than 60 parts by weight, the physical properties of rubber and the like are greatly affected, and the economical efficiency is not preferable.

The cold and heat resistant plasticizer according to the present invention is DOS, DOZ, DOA.
Can be used in combination with general plasticizers such as

The butadiene rubber to which the plasticizer of the present invention is applied is
Examples thereof include butadiene copolymer rubber such as SBR and NBR and natural rubber.

The cold- and heat-resistant plasticizer for butadiene rubber of the present invention can be compounded by a usual rubber kneading method such as an open roll, Banbury mixer, kneader blender or the like. Also, compounding agents normally used in the rubber industry,
For example, reinforcing agent, flow agent, flow accelerator, filler, softening agent,
Antiaging agents, processing aids and the like can be added as appropriate.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 To 2,000 g of polypropylene glycol (molecular weight 2000, 1.0 mol), 552 g (2.0 mol) of oleic acid and 1.3 g (0.05% by weight) of SnO were added, and after dehydration reaction at 230 ° C. for 6 hours in the presence of nitrogen gas, polypropylene glycol Georate (PPG20,
A molecular weight of about 2550) was obtained.

Example 2 Polyethylene glycol 800 g (molecular weight 400, 2.0 mol), dimer acid of linoleic acid 560 g (1.0 mol), SnO 0.68 g
(0.05% by weight) was added and esterification was carried out in the same manner as in Example 1, and then 306 g of acetic anhydride was added in the presence of nitrogen gas at 90 to 10%.
After dropwise addition at 0 ° C. and acetylation, excess acetic anhydride was removed by topping to obtain a polyethylene glycol dimer acid ester acetylated product (PEGDA, molecular weight about 1408).

Test Example 1 With respect to 100 parts by weight of NBR, 30 each of the compounds of Examples 1 and 2, dioctyl azelate (hereinafter abbreviated as DOZ), and a polyester plasticizer (ester of propylene glycol having a molecular weight of 700 and adipic acid) were used as comparative examples. Parts by weight were added to the following composition and kneaded with an open roll to prepare a rubber composition.

Medium-high nitrile NBR 100 parts by weight Stearic acid 1 〃 Carbon black SRF 40 〃 Zinc flower No. 3 〃 Accelerator DM 0.7 〃 Sulfur 1.5 〃 The rubber composition was obtained by vulcanizing at a temperature of 160 ° C for 20 minutes. The vulcanized rubber composition was subjected to a cold resistance test and a heat resistance test. The cold resistance test complies with JIS K-6301, and the heat resistance test was carried out by placing the test piece in a 120 ° C ± 1 ° C constant temperature bath and examining the weight loss after 48 hours and 10 days. The results are shown in Table-1.

Test Example 2 To 100 parts by weight of SBR, 20 parts by weight of each of the compounds of Examples 1 and 2 and DOZ as a comparative example, a polyester plasticizer (ester of propylene glycol having a molecular weight of 700 and adipic acid) were added to the following composition. Then, the mixture was kneaded with an open roll to prepare a rubber composition.

SBR # 1502 100 parts by weight Stearic acid 1 〃 Carbon black HAF 65 〃 Zinc Huasan 3 〃 Sulfur 1.75 〃 Accelerator CZ 1 〃 The rubber composition was obtained by accelerating at a temperature of 160 ° C for 10 minutes. The vulcanized rubber composition was subjected to a cold resistance test and a heat resistance test. The test method was the same as in Test Example 1. The results are shown in Table-2.

Test Example 3 Based on 100 parts by weight of NBR, polyethylene glycol (molecular weight
400) dicaprylate (PEG (400) 2K), and as a comparative example, 1,6-hexanediol dioleate (HD20) and polyethylene glycol (molecular weight 200) dicaprylate (PEG (20
15 parts by weight of each of (0) 2K) was added to the following composition and kneaded with an open roll to prepare a rubber composition.

Medium-high nitrile NBR 100 parts by weight Stearic acid 1 〃 Carbon black SRF 50 〃 Zinc Hua No. 3 5 〃 Accelerator DM 1 〃 Sulfur 1.5 〃 BHT 2 〃 The rubber composition is vulcanized at 160 ℃ for 15 minutes. A cold resistance test and a heat resistance test were performed on the obtained vulcanized rubber composition. The cold resistance test complied with JIS K-6301, and the heat resistance test was carried out by placing the test piece in a 120 ± 1 ° C. constant temperature bath and examining the weight loss after 200 hours. The results are shown in Table-3.

As can be seen from Table-1 to Table-3, the plasticizer of the present invention has excellent cold resistance, less volatile content at high temperature, and good heat resistance.

Claims (2)

[Claims] 1. A polyoxyalkylene glycol having a molecular weight of 200 to 5,000 and an alkylene group having 2 to 3 carbon atoms, and a carbon number.
The molecular weight obtained by reacting an unsaturated fatty acid having 14 to 22 or (and) a saturated fatty acid having 2 to 24 carbon atoms is 600 to 6,000.
The diester of 2. A polyoxyalkylene glycol having a molecular weight of 200 to 5,000 and an alkylene group having a carbon number of 2 to 3, and a carbon number of
A molecular weight of 600, which is obtained by reacting an unsaturated fatty acid having 14 to 22 or (and) a saturated fatty acid having 2 to 24 carbon atoms with a dicarboxylic acid or (and) polymer acid having 2 to 10 carbon atoms.
A cold- and heat-resistant plasticizer for butadiene-based rubbers, which comprises one or more selected from polyesters of up to 6,000.