GB1604725A

GB1604725A - Air entraining agents

Info

Publication number: GB1604725A
Application number: GB2300478A
Authority: GB
Original assignee: Albright and Wilson Ltd
Current assignee: Solvay Solutions UK Ltd
Priority date: 1978-05-26
Filing date: 1978-05-26
Publication date: 1981-12-16

Description

(54) AIR ENTRAINING AGENTS (71) We, ALBRIGHT & WILSON LIMITED, a British Company of P.O. Box 3, Oldbury, Warley, West Midlands, England, do hereby declare the invention, for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to air entrained cement-based building materials.

Our U.K. Specification No. 1,534,532, (corresponding to U.S. Patent No. 4,019,916) described the use of the sulphosuccinamates induding N-alkyl sulphosuccinamates as air entraining agents in cement-based building materials including mortar, cement and concrete. They have the advantage of promoting rapid mixing of air with the cement up to a total of about 16 to 24% by volume, whereupon the rate of aeration falls sharply, thus reducing the risk of over-aeration which tends to weaken the cement.

We have now discovered that certain Nalkyl sulphosuccinamates having branched chains are particularly effective air entraining agents, and give increased security against over-entrainment of air due to both overdosage and prolonged mixing of the cement mixtures. The air entraining agents used in the invention when supplied in concentrated form are normally liquid, which allows for easier handling and application.

Our invention, therefore, provides a method of making aerated cement-based building materials by agitating a mixture comprising hydraulic cement water and an air entraining agent using as the air entraining agent a water soluble N-alkyl or N-alkylpolyoxy alkylene sulphosuccinamates wherein the alkyl groups are secondary or branched chain alkyl groups having from 8 to 22 carbon atoms, or mixtures thereof with up to 80 %, by weight of the mixture, of N-alkyl or N-alkyl polyoxyalkylene sulphosuccinamates wherein the alkyl groups are primary straight chain alkyl groups.

Preferred alkyl groups in the sulphosuccinamates for use according to our invention are secondary and tertiary alkyl groups of the formula:

wherein R, is hydrogen or an alkyl group having from 1 to 4 carbon atoms, preferably a methyl group, R2 is an alkyl group having from 1 to 4 carbon atoms, preferably a methyl group and Rs is an alkyl group having from 4 to 18 and preferably from 6 to 14 carbon atoms.

Particularly preferred are tertiary-alkyl groups and especially (2 methyl-)alkyl-2 groups having an average total of from 10 to 15 carbon atoms. The sulphosuccinamates of the invention may be prepared by sulphonating, with sodium metabisulphate, the reaction product of succinic anhydride with a branched alkyl amine or an X-amino alkane, where X is integer greater than 1, preferably 2. Preferably the proportion of branched chain alkyl sulphosuccinamates is 30 to 80% by weight e.g. 40 to 70%.

Alternatively the sulphosuccinamates may be an alkyl ether sulphosuccinamate prepared from an alkyl polyoxyalkylene amine, e.g.

containing from 1 to 30, preferably 2 to 10, oxypropylene or preferably oxyethylene groups, or copolymers thereof.

Our invention may be carried out using an air entraining composition comprising a water soluble secondary or branched chain N-alkyl sulphosuccinamate and an aryl or alkaryl sulphonate hydrotrope, preferably a benzene sulphonate or alkyl benzene sulphonate hydrotrope.

Preferably the hydrotrope is sodium or potassium benzene, toulene of xylene sulphonate. Other alkyl benzene hydrotropes having up to six aliphatic carbon atoms are also operative.

The proportion of hydrotrope in the air entraining compositions is preferably from 20 to 80 b by weight, more preferably 30 to 70%, most preferably 40 to 60 h e.g.

45 to 55 Ó. Air entraining agents and compositions according to this invention are used substantially as described in our aforesaid U.K. Specification No. 1,534,532. The invention is illustrated by the following example: A sodium N (tertiary C,2 ,4 alkyl) sulphosuccinamate prepared from a tertiary C,214 alkylamine sold under the Trade Mark Primene 81R by Rohm and Hass was added to a mortar mix according to British Standard 4551 at a dosage rate of 0.015%, and at various excess dosages up to sixteenfold. All the products complied with British Standard 4887:1973. Mixtures of the sulphosuccinamates with sodium toluene sulphonate in proportions by weight of 1:1,3:2 and 7:3 gave comparable performances.

The product was then tested by the British Standard test method-BS4887:1973 using mix 1 at a dosage rate of 0.009%, on weight of cement. The following air contents were obtained: Air Content Initial mix 16.3 After further 4 mins mixing 20.2 After further 25 mins mixing 20.2 These air contents comply with the requirements of BS4887:1973.

WHAT WE CLAIM IS: 1. A method of making aerated cement based building materials by agitating a mixture comprising hydraulic cement, water and an air entraining agent, which comprises using as the air entraining agent a water soluble Alkyl or N-alkylpolyoxy alkylene sulphosuccinamate wherein the alkyl groups are secondary or branched chain alkyl groups having from 8 to 22 carbon atoms; or mix tures thereof with up to 8091. by weight of N-alkyl or N-alkylpolyoxy alkylene sulphosuccinamates wherein the alkyl groups are primary straight chain akyl groups.

2. A method according to claim 1, wherein the sulphosuccinamates are N-alkyl sulphosuccinamates having (2-methyl)-alkyl-2 groups with an average total of from 10 to 15 carbon atoms each, or mixtures thereof with up to 700/ by weight of N-alkyl sulpho succinamates wherein the alkyl groups are straight chain alkyl groups.

3. A method according to claim 1 substantially as described herein with reference to the example.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

U.K. Specification No. 1,534,532. The invention is illustrated by the following example: A sodium N (tertiary C,2 ,4 alkyl) sulphosuccinamate prepared from a tertiary C,214 alkylamine sold under the Trade Mark Primene 81R by Rohm and Hass was added to a mortar mix according to British Standard 4551 at a dosage rate of 0.015%, and at various excess dosages up to sixteenfold. All the products complied with British Standard 4887:1973. Mixtures of the sulphosuccinamates with sodium toluene sulphonate in proportions by weight of 1:1,3:2 and 7:3 gave comparable performances.

The product was then tested by the British Standard test method-BS4887:1973 using mix 1 at a dosage rate of 0.009%, on weight of cement. The following air contents were obtained: Air Content Initial mix 16.3 After further

4 mins mixing 20.2 After further

25 mins mixing 20.2 These air contents comply with the requirements of BS4887:1973.

WHAT WE CLAIM IS: 1. A method of making aerated cement based building materials by agitating a mixture comprising hydraulic cement, water and an air entraining agent, which comprises using as the air entraining agent a water soluble Alkyl or N-alkylpolyoxy alkylene sulphosuccinamate wherein the alkyl groups are secondary or branched chain alkyl groups having from 8 to 22 carbon atoms; or mix tures thereof with up to 8091. by weight of N-alkyl or N-alkylpolyoxy alkylene sulphosuccinamates wherein the alkyl groups are primary straight chain akyl groups.
2. A method according to claim 1, wherein the sulphosuccinamates are N-alkyl sulphosuccinamates having (2-methyl)-alkyl-2 groups with an average total of from 10 to 15 carbon atoms each, or mixtures thereof with up to 700/ by weight of N-alkyl sulpho succinamates wherein the alkyl groups are straight chain alkyl groups.
3. A method according to claim 1 substantially as described herein with reference to the example.