JPH06116500A - Improved paving asphalt composition - Google Patents

Abstract

PURPOSE:To obtain a bitumene modifier which can give a paving asphalt mix ture lowered in application and compaction temperatures without detriment to the properties such as abrasion resistance and having a shortened curing time before opening traffic by mixing two specified copolymers with each other. CONSTITUTION:A bitumene modifier is obtained by mixing a copolymer prepared by polymerizing as the principal components 25-97wt.% ethylene, 2-60wt.% 1-10C alkyl (meth)acrylate and 1-15wt.% unsaturated epoxide with a copolymer prepared by polymerizing as the principal components 34-99wt.% ethylene with 0-60wt.% 1-10C alkyl (meth)acrylate and 1-6wt.% unsaturated carboxylic anhydride. By mixing this modifier with a paving asphalt, the application and compaction temperatures of the obtained paving asphalt mixture can be lowered without detriment to the properties, such as abrasion resistance, and the curing time before opening traffic can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bitumen modifier used for producing modified asphalt for pavement.

[0002]

2. Description of the Related Art Various polymer materials such as rubber, thermoplastic resin and thermoplastic elastomer are added to improve service performance such as flow resistance, durability, crack resistance and adhesion of pavement asphalt. It is already well known to do.

In the modified asphalt for rubber pavement, SB
R latex and the like are generally used, and the addition amount thereof is about 3 to 5% by weight in terms of solid content. Rubber / resin-based pavement modified asphalt is usually SBR and EV as thermoplastic resin.
A, EEA, SIS, SB as thermoplastic elastomer
Polymers having properties of both rubber and resin such as S are used. The added amount is about 5 to 7 in terms of solid content.
% By weight.

However, the base asphalt for paving, which is used as the modified asphalt for paving, has an extreme difference in the effect of addition of the modifying material between the base asphalt for paving, even if the JIS standard is satisfied.

After the oil shock, due to the multi-regionalization of crude oil import destinations and the advancement of petroleum refining technology, the asphalt mixture is less glossy than the conventional asphalt base asphalt, and the asphalt originally has it. The rheological properties, etc., tended to be insufficient. Regarding the modified asphalt for pavement, the service performance such as flow resistance, abrasion resistance, durability, crack resistance, and adhesion will differ depending on the oil refinery manufacturer supplying the base asphalt for pavement and its oil refinery. Therefore, the amount of the asphalt modifier added tends to increase in order to obtain the modified asphalt for pavement having good characteristics. For this reason, there has been a problem that the high temperature viscosity is extremely increased, the pavement temperature of the modified asphalt mixture for pavement is increased, and the curing time to the traffic open temperature is extended accordingly.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention is to improve flow resistance, wear resistance, durability, crack resistance and adhesion to all pavement base asphalts used for pavement modified asphalt. It is an object of the present invention to provide a bitumen reforming material that secures service performances such as the above, lowers the pavement temperature and the compaction temperature of the modified asphalt mixture for pavement, and can shorten the curing time to the traffic open temperature accompanying it.

[0007]

That is, according to the present invention, ethylene is 25 to 97% by weight, and the number of carbon atoms of the alkyl group is 1.
10 to (meth) acrylic acid alkyl ester 2 to 60
Wt% and a copolymer (a) obtained by polymerizing 1 to 15 wt% of an unsaturated epoxide as a main component, and ethylene 3
A copolymer obtained by polymerizing 4 to 99% by weight, 0 to 60% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms, and 1 to 6% by weight of an unsaturated dicarboxylic acid anhydride as main components. A bitumen modifier comprising a mixture with (b).

[0008]

When the mixture of the copolymer (a) and the copolymer (b) is used as the bitumen modifier, the performance characteristics of the asphalt for paving, particularly the softening point, the viscosity, the gripping force and the adhesive force of the asphalt can be significantly improved. The composition can be homogenized in a short time after the modifier is added to the asphalt for paving. The reason for causing this modification effect is not clear in detail, but the epoxy group in the copolymer (a) is ring-opened by the acid anhydride group in the copolymer (b) or the functional group in the asphalt, so that the interpolymer and the polymer can be separated from each other. Cross-linking partially occurs between asphalt, softening point of asphalt,
It is considered to be caused by the increase in viscosity, gripping force and adhesive force.

Examples of the asphalt used in the present invention include natural asphalt for paving, natural asphalt such as lake asphalt, semi-blown asphalt, straight asphalt modified by partially using blown asphalt, tar-modified straight asphalt, and the like. One kind or a mixture of two or more kinds thereof is used. However, the penetration degree of the asphalt composition for pavement of the present invention is 30 to 1 at 100C for 5 seconds at 25 ° C.
50, it is necessary to select the penetration and softening point of the asphalt to be used so that the softening point is in the range of 40 to 100 ° C.

In the present invention, 94 to 60% by weight of ethylene, 5 to 25% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms and 1 to 15% by weight of an unsaturated epoxide are main components. The copolymer (a) polymerized as is used as one component of the bitumen modifier.

The (meth) acrylic acid alkyl ester used as a component constituting the copolymer (a) has an alkyl group having 1 to 10 carbon atoms, and the alkyl group is linear or branched. It may also include a cycloalkyl group. Specific preferred examples thereof include methyl methacrylate, ethyl acrylate, and acrylic acid n-.
Examples include butyl, isobutyl acrylate, and 2-ethylhexyl acrylate. These (meth) acrylic acid alkyl esters may be used alone or in combination of two or more. In addition, in this specification, (meth) acrylic acid means acrylic acid and / or methacrylic acid.

The amount of the (meth) acrylic acid alkyl ester in the copolymer (a) is from 2 to 60% by weight, and if it is out of this range, the dispersibility in asphalt is lowered. Examples of the unsaturated epoxide used as a component constituting the copolymer (a) include aliphatic glycidyl esters or ethers such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate, glycidyl itaconic acid, glycidyl acrylate, and glycidyl methacrylate; Cyclic glycidyl ester or ether, such as 2-cyclohexene-1-glycidyl ether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexene-4-glycidyl carboxylate, 5-norbornene-2-methyl-2-glycidyl carboxylate, Endocis-bicyclo (2.2.
1) -5-heptene-2,3-diglycidyl carboxylate. Of these, glycidyl methacrylate is preferable. One kind or two or more kinds of unsaturated epoxides are used.

The amount of unsaturated epoxide in the copolymer (a) is 1 to 15% by weight, and if it is less than 1% by weight, the effect of improving the performance characteristics of the paving binder is poor, and if it exceeds 15% by weight, the reactivity is high. As a result, the dispersibility in asphalt decreases.

Other copolymerizable components which can be used in a small amount as the component constituting the copolymer (a) include α-olefins such as propylene and butene-1; vinyl ether, vinyl acetate, styrene, acrylonitrile and the like.

The copolymer (a) obtained by copolymerizing the above components has a flow index (ASTM D 12
2.16 Kg, measured at 190 ° C.) in accordance with 38 standards
It is preferably 50 dg / min, more preferably 5 to 20 dg / min.

Further, in the present invention, in addition to the copolymer (a), 34 to 99% by weight of ethylene, 0 to 60% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms, and unsaturated. The copolymer (b) obtained by polymerizing 1 to 6% by weight of a dicarboxylic acid anhydride as a main component is also used as another component of the bitumen modifier.

As the (meth) acrylic acid alkyl ester used as the component constituting the copolymer (b), those exemplified as the component constituting the copolymer (a) can be used in exactly the same manner. The amount of the (meth) acrylic acid alkyl ester in the copolymer (b) may be 0, but is preferably 2 to 50% by weight from the viewpoint of dispersibility in asphalt.

Examples of the unsaturated dicarboxylic acid anhydride used as a component constituting the copolymer (b) include maleic anhydride, itaconic anhydride, citraconic anhydride, and tetrahydrophthalic anhydride, and maleic anhydride is preferred. One kind or two or more kinds of unsaturated dicarboxylic acid anhydrides are used.

The amount of the unsaturated dicarboxylic acid anhydride in the copolymer (b) is 1 to 6% by weight, and if it exceeds 6% by weight, it reacts excessively with the copolymer (a), so that the dispersibility in asphalt decreases. It is not suitable because

Other copolymerizable components which can be used in a small amount as the component constituting the copolymer (b) include the same monomers as exemplified for the copolymer (a).

The melt flow index of the copolymer (b) (measured under the same conditions as the copolymer (a)) is from 1 to
It is preferably 50 dg / min.

Copolymer (a) and copolymer (b)
The mixing ratio of (a) / (b) is 0.1-10.
It is preferable to select within the range. A more preferable mixing ratio varies depending on the epoxy group content in the copolymer (a) and the acid anhydride group content in the copolymer (b). A particularly preferred mixing ratio is such that the molar ratio of the acid anhydride group in the copolymer (b) to the epoxy group in the copolymer (a) is in the range of 0.5 to 1.

When the amount of the copolymer (b) used is less than the above range, the copolymer (a) and the copolymer (b) are used.
When used together, the pavement temperature can be lowered, and the effect of the bitumen modifier of the present invention that the bitumen modifier can be uniformly dispersed in asphalt in a short time becomes insufficient. On the other hand, the copolymer (a)
If the amount used is less than the above range, the amount of epoxy groups in the bitumen modifier is insufficient, and the ring-opening cross-linking reaction sufficiently improves the softening point, viscosity, gripping force and adhesive force of the asphalt. Can not.

The asphalt composition for paving of the present invention comprises:
It is preferable that the compound (c) which promotes the reaction between the epoxy group in the copolymer (a) and the acid anhydride functional group in the copolymer (b) or the like is further added. Examples of the compound (c) as such an epoxy group ring-opening reaction accelerator include tertiary amines such as dimethyluralylamine,
Dimethyl stearylamine, N-butylmorpholine,
N, N-dimethylcyclohexylamine, benzyldimethylamine, pyridine, dimethylamine-4-pyridine, methyl-1-imidazole, tetramethyl-ethylenediamine, tetramethylguanidine, triethylenediamine, tetramethyl-ethylenediamine, tetramethylguanidine, triethylenediamine , Tetramethylhydrazine, N, N-dimethylpiperazine, N, N,
N ', N'-tetramethyl-1,6-hexanediamine; and tertiary phosphines, such as triphenylphosphine, with tertiary amines being especially preferred.

The compound (c) is preferably used in an amount sufficient for the bitumen modifier comprising the copolymer (a) and the copolymer (b) to effectively play a role of promoting at least partial crosslinking. . Usually, it is 0.1 to 20 parts by weight with respect to 100 parts by weight of the bitumen modifier.

The modified asphalt for pavement according to the present invention may contain various conventionally known thermoplastic polymer modifiers in addition to the bitumen modifier. Such thermoplastic polymer modifiers are roughly classified into rubbers, thermoplastic elastomers and thermoplastic resins.

As the rubber, one or more kinds of natural rubber and various synthetic rubbers can be used. The rubber may be solid or latex, but the Mooney viscosity is 10 to 1
It is preferably about 50. The synthetic rubber, styrene-butadiene copolymer, polychloroprene rubber, acrylonitrile-butadiene copolymer, isobutylene-isoprene copolymer, polyisoprene rubber, polybutadiene, ethylene-propylene copolymer, styrene-isoprene copolymer, Examples thereof include silicone rubber, fluororubber, epichlorohydrin copolymer, polyacrylic acid ester and the like.

As the thermoplastic resin, polyethylene, polypropylene, polybutene, polystyrene, polyvinyl chloride, vinylidene chloride, polyvinyl acetate, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-
Examples thereof include ethyl acrylate copolymers, styrene-alkyl acrylate copolymers, acrylonitrile-butadiene-styrene copolymers, acrylic resins, polyamides, saturated polyesters, petroleum resins, fluororesins and natural rosins.

As the thermoplastic elastomer, styrene-butadiene-styrene block copolymer, styrene-
Examples thereof include isoprene-styrene block copolymers, styrene-ethylene-butadiene-styrene block copolymers, polyester elastomers, polyurethane elastomers, polyethylene butylene rubber graft polymers, polyolefin elastomers and the like.

The addition amount of the bitumen modifier of the present invention is
A suitable range is 7 to 1% by weight of bitumen modifier with respect to 93 to 99% by weight of asphalt. If it is less than 1% by weight, the effect of addition of the bitumen modifier is not sufficient. On the other hand, depending on the amount of unsaturated epoxide in the copolymer (a), if the amount of the bitumen modifier exceeds 7% by weight. The melt viscosity of asphalt increases and the pavement temperature cannot be lowered.

When a conventional thermoplastic polymer modifier is used in combination in the asphalt composition for pavement, 20 to 200 parts by weight of the thermoplastic polymer modifier are added to 100 parts by weight of the bitumen modifier. It is preferably used in a proportion of about 1 part. Further, the total amount of the bitumen modifier and the thermoplastic polymer modifier is preferably used in the range of 1.5 to 15 parts by weight with respect to 100 parts by weight of asphalt.

The bitumen modifier of the present invention is used as a pavement asphalt composition of a mixture for base layers and surface layers of general road pavement, as well as asphalt for pavement such as factory yard pavement, container yard, truck terminal, etc. which are particularly heavily loaded. Used as a composition. In addition, it is particularly suitable as a bitumen modifier for asphalt compositions such as bridge surfaces and viaducts that require durability and weather resistance.

[0033]

EFFECTS OF THE INVENTION By using the bitumen modifier of the present invention, flow resistance, abrasion resistance, durability, crack resistance, and adhesiveness can be obtained for all pavement base asphalt used in pavement modified asphalt. In-service performance such as was secured. In addition, the time required for mixing and preparing the modified asphalt mixture for pavement can be shortened, and the pavement temperature and rolling pressure of the modified asphalt mixture for pavement can be reduced to shorten the curing time to the traffic open temperature. Traffic congestion can be reduced.

[0034]

Example 1 To 99 kg of pavement straight asphalt (penetration 60/80, manufactured by Kyokuto Sekiyu K.K.) heated and melted at 160 ° C., 68 wt% of ethylene, 24 wt% of ethyl acrylate and methacrylic acid were used. Copolymer of 8% by weight of glycidyl (LOTADERAX 8660, trade name, manufactured by Elf Atchem) and 90% by weight of ethylene, 8% by weight of ethyl acrylate and 2% by weight of maleic anhydride (LOTADER AX 4700, trade name, 2 kg (manufactured by Elf Atochem Co.) was added and stirred and dissolved until uniform, and then the heating and melting temperature was further raised to 180 ° C. and stirred to obtain a paving asphalt composition.

30 × 3 of this asphalt composition for pavement
The test piece was evaluated by putting it in a 0 × 5 cm mold and performing compaction so that the compaction degree was 100 ± 1% of the compaction degree in the Marshall test. The results shown in Table 1 were obtained. .

Example 2 In place of 2 kg of the ethylene-ethyl acrylate-maleic anhydride copolymer used in Example 1, 64% by weight of ethylene,
32% by weight of ethyl acrylate and 2 maleic anhydride
2% by weight of dimethylstearylamine in the copolymer of% by weight
Polymer to which is added (LOTADER XX 127
An asphalt composition for paving was obtained in the same manner as in Example 1 except that 2 kg of the product (trade name, manufactured by Elf Atchem Co.) was used as a bitumen modifier. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1.

Example 3 Asphalt composition for paving as in Example 1 except that the three polymers used in Examples 1 and 2 were used as bitumen modifiers in the proportions shown in Table 1. I got a thing. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1.

Comparative Example 1 An asphalt composition for pavement was prepared in the same manner as in Example 1 except that only 4 kg of the ethylene-ethyl acrylate-glycidyl methacrylate copolymer used in Example 1 was used as a bitumen modifier. Obtained. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2 Table 1 shows the results of evaluation of straight asphalt in the same manner as in Example 1 without using the bitumen modifier.

[0040]

[Table 1]

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[Procedure amendment]

[Submission date] March 31, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

[0034]

Example 1 To 99 kg of pavement straight asphalt (penetration 60/80, manufactured by Kyokuto Sekiyu K.K.) heated and melted at 160 ° C., 68 wt% of ethylene, 24 wt% of ethyl acrylate and methacrylic acid were used. Copolymer of 8% by weight of glycidyl (LOTADERAX 8660, trade name, manufactured by Elf Atchem) and 90% by weight of ethylene, 8% by weight of ethyl acrylate and 2% by weight of maleic anhydride (LOTADE R 4 700, trade name) (Manufactured by Elf Atochem Co., Ltd.) and stirred and dissolved until uniform, and then the heating and melting temperature is further raised to 180 ° C. and stirred,
An asphalt composition for paving was obtained.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction content]

[0040]

[Table 1]

Claims (6)

[Claims] 1. 25 to 97% by weight of ethylene, 2 to 60% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms, and 1 to 1 of an unsaturated epoxide.
Copolymer (a) obtained by polymerizing 5% by weight as a main component, ethylene 34 to 99% by weight, (meth) acrylic acid alkyl ester having 1 to 10 carbon atoms in the alkyl group, 0 to 60% by weight and unsaturated Dicarboxylic acid anhydride 1
A bitumen modifier comprising a mixture with a copolymer (b) obtained by polymerizing 6% by weight as a main component. 2. The bitumen modifier according to claim 1, wherein the weight ratio of the copolymer (a) to the copolymer (b) is 0.1 to 10. 3. A composition comprising 93-99% by weight of asphalt and 7-1% by weight of a bitumen modifier.
The bitumen modifier is ethylene 25 to 97% by weight,
Copolymer (a) obtained by polymerizing 2 to 60% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms and 1 to 15% by weight of an unsaturated epoxide, and ethylene 34 to 99. A copolymer (b) obtained by polymerizing, as a main component, by weight, 0 to 60% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 10 carbon atoms, and 1 to 6% by weight of an unsaturated dicarboxylic acid anhydride. An asphalt composition for pavement, which is a mixture with. 4. The bitumen modifier according to claim 1, wherein the weight ratio of the copolymer (a) to the copolymer (b) is 0.1 to 10. 5. A compound (c) capable of accelerating the reaction between an epoxy group and an acid anhydride group is added.
The composition as described. 6. The composition according to claim 5, wherein the compound (c) is a tertiary amine.