DE2225698C3 - Aqueous siloxane bag slip agent for tire manufacture - Google Patents

Description

(CH ₃ ) ₃ SiO [(CH ₃ ) ₂ SiOUCH ₃ SiO] ₇ Si (CH ₃ ) ₃ O

! Ii

(CH ₂ J ₃ O (C ₂ H ₁ O) ₂₁ (C ₃ H ₆ O) ₂₄ CCH ₃

(C) about 41% mica with a grain size of about 0.044 mm, (D) about 0.3% carboxymethyl cellulose, (E) about 1% soy lecithin and (F) about 40.7% water.

6. Agent according to claim 1, characterized in that it consists essentially of
(I) 3 to 40 weight percent of a copolymer of an alkylmethylsiloxane having 1 to 20 carbon atoms in the alkyl group and a polyalkylene glycol from ethylene oxide units, propylene oxide units or combinations of Äthylienoxid- and propylene oxide units as alkylene oxide units, having a viscosity of at least 200 centistokes at 25 ^Ü C and Contains 5 to 50 percent by weight of the alkylmethylsiloxane,
(H) 25 to 50 percent by weight mica with a grain size corresponding to sieve openings of 0.193 to 0.021 mm,

(III) 0.1 to 5 weight percent (1) carboxymethyl cellulose or (2) carboxyethyl cellulose,

(IV) 0.1 to 5 weight percent lecithin and
(V) 15 to 55 percent by weight water.

7. Agent according to claim 6, characterized in that it consists essentially of (I) about 23% of a copolymer of the average formula

(CH ₃ ) ₃ Si [OSi (CH ₃ ) ₂ ] ₄₈₀ [OSiCH ₃ ] ₃₀ OSi (CH ₃ ) ₃

! ^l;

(CH ₂ ) ₃ (OC ₂ H ₄ ) ₂₆ (OC ₃ H _e ) _2e OCCH ₃

(II) about 41% mica with a grain size of about 0.044 mm, (JIl) about 1% carboxymethyl cellulose, (IV) about 1% soy lecithin; and (V) about 34% water.

The use of methylpolysiloxanes as mold release agents or release agents for tires and other plastic products is known. In the manufacture of tires, the methylpolysiloxane fluid is sprayed onto the mold to separate the tire from the surface of the metal mold. For such purposes, dimethylpolysiloxane alone is an excellent release agent.
During the manufacture of the tire, however, the actual molding of the tire takes place by inflating a rubber sack inside the "green" tire carcass, which presses the tire against the mold . The sack must then be released smoothly from the inside of the vulcanized tire without any defects in shape. The material used as the release agent between the tire carcass and the bag is commonly referred to as the bag or blank lubricant. Through the invention

3 4

The siloxanes used in the present invention are said to improve the effectiveness of such lubricants

will. Alkylmethylsiloxanes. which by their nature are liquid

In U.S. Patent No. 3,532,624 U, they are sackcloth and have a viscosity of at least IQOU centi-

Solvent-based lubricants described. Have this stoke up to 25 ° C. The upper bound for that

Medium is used in the tire industry with a high viscosity is not critical, so that it is up to 10 MiIH-

follow used. Because of the increasing extent onen Centistoke at 25 ⁰ C can range. The siloxane

Impending air pollution , however, it is often (A) can, in other words, a non-flowing

undesirable to be hydrocarbon _{solvent j n} large rubber. The alkylraethylsiloxane can be a

Use larger scale. There is therefore a need for dimethylsiloxane, which is preferred, or a suloxane

for an aqueous system with the equally good Er- iq from units of the formula RCH ₃ SiO, where R

an alkyl group with 2 to 20 carbon atoms are achieved as with the known means,

be able. By the invention such a means z. B. ethyl, isopropyl, butyl, octyl, dodecyl or

created- C ₈₀ H ₄₁ means. These alkylmethylsiloxanes can

The invention aims to provide a bag slip agent which has hydroxyl groups as end groups , or which improves the life of the bag, fewer trihydrocarbylsilyl groups can be fired at a lower overall cost. The alkylmethylsiloxane fluids can also be produced by manufacturers, small amounts of _{RSiO 3 / r} and SiO ^ units can be lost and the need for use can be avoided if stored for a long time without settling. Liquids of this type are generally eliminated with organic solvents. know, and need procedures for their manufacture

Such a means has now been found which cannot be explained from * o.

(A) 1 to 20 weight percent of an alkylmethyl component (B) must have a molecular weight of siloxane fluid having 1 to 20 carbon atoms of at least 500. It may be a Polyäthylenin the alkyl group and a viscosity of ⁰⁰ ^ ^'or polypropylene glycol or a copolymer of at least 1,000 centistokes at 25 ^C C thereof. It is the combination of (A) and (B),

(B) 2 to 20 weight percent (1) Polyalky'lenglycolen ^{25, the bag the richti} S ^e imparts lubricity. The molecular weight at least 500 vo.i ^{in Herstellun} g ^{of the} polyalkylene glycol used wherein the alkylene oxide Äthylenoxidein- initiator is not critical, and, if desired, can cure oxide, propylene oxide units or combination ^the polyglycol ^mi * monovalent groups known functions of Äthylenoxid- and Propylenoxidein- endblocked being.

are cure, or (2) copolymers of alkyl ³ ° component (B) can also be a copolymer of methylsiloxanes and polyalkylene glycols with ^an alkylmethylsiloxane and a polyalkylene with a viscosity of at least? 00 centistoke ^ ⁰¹ ' ^whose alkylene oxide units are ethylene at 25 ° C, in which oxide units aik ^or propylene oxide units or combinations of the ethylene oxide units, propylene oxide units or ^{both are "These} copolymers are generally beKombinationen of Äthylenoxid- and propylene ^{35 known} commercial products and examples of the Strukoxideinheiten and ^structures containing 5 to 50 weight · ^{the for the} inventive needs percent of alkylmethylsiloxane ^{contained> can be found in} numerous patents, ζ. Β

(C) 25 to 50 percent by weight mica having a ^de "" ^ ^A '- ^P / ^th i ^Sri if ^s _u ^{3 4} ^ ^{2 1} ^ ^{2' 28} f ^ LZ particle size corresponding to sieve openings of 3,057,901, Canadian Patent No. 669,881 0 193 to 0 021 mm ⁴ ° ^the Belgian patents 739 312 and 730 686

(D) from 1 to 5 percent by weight of (1) carboxymethyl ^and French patents 1 259 241 and cellulose or (2) carboxyethyl cellulose, ^{1 353} ° ⁷⁰ · ^{In these} copolymers, the alkylene

(E) 0.1 to 5 percent by weight of lecithin and oxide portion have hydroxyl end groups or through

(F) 15 to 55 percent by weight water. monovalent organic groups, e.g. B. hydrocarbon

45 residues of substances, halogenated hydrocarbons, carboxyl

If desired, component (B) (2) can be a groups, SiR ₃ groups, urethane groups or acyl

Mixture of a polyalkylene oxide and a co groups, be end-blocked. The polyalkylene oxide component

polymer from an alkylmethylsiloxane and alkylene is with the siloxane portion over a silicon-carbon

be oxide. fabric-bond linked, the linking group

Furthermore , a mean was found that consists of 50 between the polyalkylene oxide and the siloxane portion

can for example be a hydrocarbon or

(I) be 3 to 40 percent by weight of a polymer of a halogenated hydrocarbon group or contain ether, an alkylmethylsiloxane with 1 to 20 carbon, ester, sulfide or other bonds. The material atoms in the alkyl group and a poly-copolymer can have linear, branched or cyclic alkylene glycol composed of ethylene oxide units, have a Pro- 55 structure and have a pylene oxide chain or combinations of or more alkylene oxide units on any silicon atoms.
Ethylene oxide and propylene oxide units as the silox content of the copolymer can RSiO ₃ / _a -, alkylene oxide units with a viscosity of R ₂ SiO, R ₃ SiO ₁ ^ or SiOj units in each Kotnbi- at least 200 centistokes at 25 ° C, the 5th up nation of these units included.

50 weight percent of the alkylmethylsiloxane 60 The general formula for such copolymers

contains, reads

(II) 25 to 50 percent by weight mica with a

Particle size corresponding to sieve openings of ι _Ώ c: .- »1 r _n > oja η ι

0.193 to 0.021 mm, R "S> O4 J" R _m SB _v O 4 _ ^ _, |

(III) 0.1 to 5 weight percent (1) carboxymethyl-65
cellulose or (2) carboxyethyl cellulose,

(IV) 0.1 to 5 percent by weight of lecithin and wherein R and R 'are alkyl radicals with 1 to 20 carbon - (V) 15 to 55 percent by weight of water. atoms, "a number from 0 to 3, a number from 0 to 2,

2,225,898

y 1 or 2, b 0 or an integer, c an integer with at least the value 1 and B the group

- R ⁸ (OR ³ ) _r , QR <

where R ^{8 is} a linking group as defined above, R ^s

-CHaCH ₈ - or -CH ₈ C-

I.
CH ₃

and R ⁴ denotes any of the abovementioned monovalent end groups and d has a value such that the ^{total molecular weight of the OR 3} groups is preferably at least 10-10.

The component (I) used in the present invention has that given in the previous section general formula and may, for example, have any of the structures shown in any of the above Patents are given. However, there are some critical limitations for component (I), which do not apply to (B) (2).

Thus, the viscosity of (I) must be at least 200 centistokes at 25 ° C. and the siloxane content must be in the range from 5 to 50 percent by weight, based on the total weight of (1).

Carboxymethyl cellulose or carboxyethyl cellulose are used as thickeners in the agents according to the invention used. The substances mentioned are generally known and are commercially available. It will believed that the use of carboxymethyl cellulose would provide a more stable agent and that Makes preparation of the remedy easier.

The lecithin used for the purposes of the invention is a naturally occurring substance and can come from any source. It can expediently be obtained from soybeans.

The compositions according to the invention can be prepared by mixing the constituents in any desired combination be generated. One way to make them is to add the thickener to water give, then all the ingredients except the mica in an effective mixing device to mix in and finally add the mica while mixing intensively. If so desired the whole combination can be passed through a colloid mill for better dispersion to achieve. Furthermore, the agent is apparently best prepared in such a way that the alkylmethylsiloxane liquid is emulsified before mixing with the other ingredients.

The agents according to the invention are distinguished by great stability and can be used without settling transported and stored for a long time. When they are then sprayed on the technical equipment used by rubber processors, they give excellent separation of the Sacks from the tire. This combination of properties means that the tire manufacturer has a ready-to-use Obtain a product with which they can work successfully in their manufacturing facilities can be relieved of the need to prepare bag lubricants yourself.

In addition to the above-mentioned necessary ingredients, the agents according to the invention can be smaller Amounts of other fillers, e.g. B. talc, rust inhibitors, e.g. B. sodium nitrate, germicides, e.g. B. formaldehyde, and other ingredients, e.g. B. coloring

ίο Contains substances and anti-freeze agents.

The following are those mentioned in the examples Components defined.

Dowicil 100 is a he \ amethylenetetramine-1,3-dichloropropane adduct, that in the U.S. Patent

3,228,829. It's a germieid.

The invention is illustrated in more detail by the following examples. In the examples, Me is used as an abbreviation for the methyl radical. All parts and percentages are by weight and all viscosities are measured at 25 ^n, unless otherwise specified.

example 1

A blank lubricant is prepared consisting of 14.3 _"o a 35prozenligen aqueous emulsion of a Dimethylpolysiloxanflüssigkeit with 100,000 centistokes. 12.0" _o a polyalkylene glycol of the formula

HCOC ₂ H ₄ OC ₃ H ₆ OH

(CHoOC ₂ H ₁ OC ₁ H _n OH),

with a molecular weight of 2600, 41.0% mica (0.044 mm), 0.3% carboxymethyl cellulose, 1.0 ",, Soy lecithin, 0.1% Dowicil 100 and 31.3% water. To manufacture this remedy are going to be first the glycol and the carboxymethyl cellulose mixed. Then the water, the dimethylpolysiloxane emulsion, the lecithin, dowicil and mica are added and mixed in in that order. After all ingredients are thoroughly mixed, the agent is once through a colloid mill with a Adjustment of 0.0635 cm guided. This remedy is easy to prepare, has excellent stability and gives excellent demoulding. if it is used as a bag sealant. The mean h-U initially a viscosity of 52,000 centistokes. Its viscosity is 2 days after manufacture 44,000 centisloke. 3 days later 36,000 centistokes and 18 days later 35,000 centistokes. If that Centrifugation for an average of 40 minutes at 2000 rpm, no sedimentation of glow is observed.

Example 2

If you use carboxyethyl cellulose instead of the carboxymethyl cellulose as in Example 1! will, an excellent, stable blind slip agent is obtained.

Claims (5)

Claims; 1, mold release agent for tire production, characterized in that it is in essential from (A) optionally 1 to 20 percent by weight of an alkylmetby jisiloxane liquid with 1 to 20 carbon atoms in the alkyl group and a viscosity of at least 1000 centistokes at 25 ⁰ C, optionally 2 to 20 percent by weight of a component of (1) polyalkylene glycols with a molecular weight of at least 500, in which the alkylene oxide units are ethylene oxide units, propylene oxide units or combinations of ethylene oxide and propylene oxide units, or (2) copolymers of alkylmethylsiloxanes and polyalkylene glycols of ethylene oxide units, propylene oxide units or combinations of ethylene oxide and propylene oxide units which have a viscosity of at least 200 centistokes at 25 ° C and contain 5 to 50 percent by weight of the alkylmethylsiloxane,
25 to 50 percent by weight mica with a grain size corresponding to sieve openings of 0.193 to 0.021 mm, (D) 0.1 to 5 percent by weight of (I) carboxymethyl cellulose or (2) carboxymethyl cellulose, (E) 0.1 to 5 weight percent lecithin and (F) 15 to 55 percent by weight water. 2. Means according to claim 1, characterized in that it contains as component (A) a dimethylsiloxane and from component (B) a polyalkylene glycol 3. Composition according to claim 2, characterized in that it consists essentially of (A) about 5% of a dimethylsiloxane with a viscosity of about 100,000 centistokes, (B) about 12% of a polyalkylene glycol, wherein the alkylene oxide units consist of a combination of ethylene oxide and propylene oxide units, (C) about 41% mica with a grain size of about 0.44 mm, (D) about 0.3% carboxymethyl cellulose, (E) about 1% soy lecithin, and (F) about 40.7% wiuser. 4. Composition according to claim 1, characterized in that it is a dimethylsiloxane as component (A) and as constituent (B) a copolymer of a dimethylsiloxane and a polyalkylene glycol contains. 5. Composition according to claim 4, characterized in that it consists essentially of (A) about 5% of a dimethylsiloxane having a viscosity of about 100,000 centistokes, (B) about 12% of a copolymer of the average formula