JPS635344B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified cement composition obtained by adding sorbitan higher fatty acid ester to cement. Cement compositions used in the architecture and civil engineering fields have a wide variety of uses, and the common performance requirements for these uses include good workability (kneading and coating properties) and good adhesion. These include durability, good waterproofness (no water absorption), excellent crack resistance, and no efflorescence. In improving cement compositions, various additives are used as cement admixtures for various purposes. For example, to improve freeze-thaw resistance, ether sulfate activators are used as air entraining agents.
Alkylbenzene sulfonic acid type activators, polyoxyethylene alkylaryl ethers, higher alcohol alkylene oxide adducts, etc. are used. In addition, to improve the fluidity of concrete,
As a water reducing agent, naphthalene sulfonic acid condensate, melamine sulfonic acid condensate, lignin sulfonic acid, oxycarboxylic acid, alkylene oxide type activator,
Polyoxyethylene/oxypropylene block copolymers and the like are used. Furthermore, ligninsulfonic acid, oxycarboxylic acid, sodium tripolyphosphate, etc. are used as cement hardening retarders. Furthermore, JP-A No. 57-22152 proposes adding sodium stearate, potassium stearate, etc. in the range of 0.5 to 20 g per 1 kg of cement to suppress the water absorption of the cement layer. Furthermore, in Japanese Patent Publication No. 56-51148, the general formula RO(AO) _o H (wherein R is an alkyl group having 1 to 4 carbon atoms, A is one or two alkylene groups having 2 to 3 carbon atoms, n is a number from 1 to 10). However, the above-mentioned various compounds generally do not have the waterproofing properties (effects of reducing water absorption) when fatty acid esters of polyhydric alcohols are added, or even if they do, they are not said to have sufficient effects. It's difficult. In view of these drawbacks, the present inventors have conducted intensive research and found that by adding 0.03 to 10 parts by weight of sorbitan higher fatty acid ester with an HLB of 10 or less to 100 parts by weight of cement in a cement composition, conventional products can be improved. The present inventors have discovered that the above drawbacks can be overcome, and that the waterproof properties and water absorption required for cement compositions can be reduced, and the present invention has been completed. That is, in the present invention, HLB is added to 100 parts by weight of cement.
sorbitan higher fatty acid ester with a value of 10 or less.
This is a modified cement composition obtained by adding 0.03 to 10 parts by weight. The sorbitan higher fatty acid ester used here is specified to have an HLB of 10 or less from the viewpoint of effectiveness, and those with an HLB of 8 or less are more preferable. Addition amount of sorbitan higher fatty acid ester is cement 100
0.03 to 10 parts by weight, preferably 0.05 parts by weight
~8 parts by weight, more preferably 0.1 to 6 parts by weight. If it is less than 0.03 parts by weight, the desired effect will not be obtained, and if it exceeds 10 parts by weight, there will be a drawback that the physical properties of the cement composition will be deteriorated. The sorbitan higher fatty acid esters mentioned here include sorbitan and higher fatty acids, specifically oleic acid, linoleic acid, linoleic acid, capric acid, pelargonic acid, capric acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, and palmitic acid. Saturated and unsaturated higher acids such as margaric acid, stearic acid, nonadecanoic acid, arachidic acid, hebenic acid, ω-cyclohexyl fatty acid, ω-phenyl fatty acid, ω-cyclopentenyl fatty acid, oxyfatty acid, abietic acid, tall oil fatty acid, etc. It is an ester with fatty acids. Specific examples of sorbitan higher fatty acid esters include sorbitan monooleate, sorbitan sesquiolate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monolaurate, sorbitan trioleate, sorbitan tritol oil fatty acid ester, and sorbitan monotol oil fatty acid ester. , sorbitan higher fatty acid esters such as sorbitan castor oil ester. Further, in the composition of the present invention, other components commonly used in cement can also be used in combination. For example, metal chlorides such as calcium chloride and sodium chloride, known cement hardening accelerators such as organic amines such as triethanolamine, hardening retarders such as lignin sulfonic acid, oxycarboxylic acid, and sodium tripolyphosphate, and nitrous acid. Various products such as known reinforcing steel rust preventive agents such as nitrites such as sodium and calcium nitrite, water reducing agents such as naphthalene sulfonic acid condensates, melamine sulfonic acid condensates, lignin sulfonic acids, oxycarboxylic acids, and alkylene oxide activators. can be given. Also,
Water-soluble polymers such as polyvinyl alcohol, methylcellulose, hydroxyethylcellulose, and ethylhydroxyethylcellulose can also be used in combination. In addition, including polyvinyl acetate emulsion, vinyl acetate-ethylene copolymer, vinyl acetate-vinyl persatinate copolymer, vinyl acetate-acrylic ester copolymer, styrene-acrylic ester copolymer, styrene-butadiene It is also perfectly acceptable to use in combination various synthetic resin emulsions such as copolymers and redispersible synthetic resin compositions prepared by adding an anti-caking agent to these emulsions and spray drying. Sorbitan higher fatty acid ester used in the present invention can be added in the same manner as in the case of cement admixtures, for example, by pre-mixing it in kneading water, or adding it to a mixture of cement, aggregate, and water. Means such as adding it during kneading can be adopted. EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto. Example 1 Powders containing 100 parts by weight of cement, 100 parts by weight of silica sand No. 7, and 0.2 parts by weight of Hymetrose 90SH-4000 (manufactured by Shin-Etsu Chemical Co., Ltd.; hydroxypropyl methyl cellulose) were prepared. 100 parts by weight of this powder, 30 parts by weight of water,
0.2 parts by weight of Span 85 (manufactured by Kao Atlas Co., Ltd.: sorbitan triolate, HLB 1.8) was added and mixed uniformly to obtain a cement mortar composition. This cement mortar composition was tested for water absorption and normal adhesive strength according to the Cement Filler Judgment Standards of the Japan Housing and Urban Development Corporation. The results are shown in Table 1. Example 2 The same procedure as in Example 1 was carried out except that 4.6 parts by weight of Span 85 was used. The results are shown in Table 1. Comparative Example 1 The same procedure as Example 1 was carried out except that Span 85 was not used. The results are shown in Table 1. Comparative Example 2 Tween 80 (polyoxyethylene sorbitan monooleate,
The same procedure as in Example 1 was conducted except that HLB15) was used.
The results are shown in Table 1. Comparative Example 3 DK Ester F-110 (Daiichi Kogyo Yakuhin Co., Ltd.), which is a commercially available sucrose ester, was used instead of Span 85 in Example 1.
The procedure was carried out in the same manner as in Example 1, except that HLB11), manufactured by M. Co., Ltd., was used. The results are shown in Table 1. The results of these Examples and Comparative Examples are shown in Attached Table 1, and it is clear that the cement composition of the present invention has low water absorption, excellent waterproof properties, and excellent adhesive strength. It goes without saying that the present invention can also be applied to cement compositions other than those shown in the Examples. 【table】

Claims (1)

[Claims] 1. A modified cement composition obtained by adding 0.03 to 10 parts by weight of sorbitan higher fatty acid ester having an HLB of 10 or less to 100 parts by weight of cement.