JPS62236848A - Production of polyvinyl chloride resin for use in pasting - Google Patents

Abstract

PURPOSE:To obtain the titled resin which gives plastisol having a low viscosity and excellent foamability by adding a sorbitan ester and a polyoxyethylene phenyl ether to a PVC latex and spray-drying the mixture. CONSTITUTION:A vinyl chloride polymer latex (A) obtd. by polymerizing vinyl chloride is mixed with a compd. (B) of formula I (wherein R is a 12-18C alkyl or an alkenyl; X is H or a group of formula II or III; and n is a number of 4-20) (e.g., sorbitan monolaurate) and 0.05-0.5wt% (based on the amount of the component A) compd. (C) of formula IV (wherein R is an 8-9C alkyl) (e.g., polyoxyethyl octylphenyl ether) in a weight ratio of C to B of not higher than 1. The resulting polymer latex is spray-dried to obtain a polyvinyl chloride resin to pasting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a polyvinyl chloride resin for paste processing (hereinafter referred to as paste vinyl chloride). More specifically, the present invention relates to a method for producing a paste PVC that provides a plastisol with low viscosity and has good foaming processability.

[Conventional technology]

There are many properties required of paste PVC, among which plastisol viscosity is required to be low in order to facilitate sol preparation, sol transfer, and sol processing.

Factors on the paste PVC side that control the viscosity of plastisol include resin particle size, particle size distribution, and type and amount of emulsifiers and other additives used during polymerization.

There are drying and pulverizing conditions, etc., and formulation factors during sol preparation include plasticizers, fillers, and pigments.

There are types and amounts of stabilizers and other components, but many of these factors are tied to the needs of resin manufacturing technology or final product quality, and cannot be selected freely from the perspective of reducing sol viscosity. do not have. Usually, for the purpose of reducing viscosity, sorbitan esters, glycerin esters 1
Adding a small amount of sorbitan esters, alkylphenyl ethers, fatty acid esters, sulfosuccinic acid ester salts, and alkyl sulfuric ester salts having a repeating unit of oxyethylene in the molecule, or using a linear hydrocarbon solvent as a diluent for plastisol, Aromatic hydrocarbon solvents are being used. Among these, the use of a diluent increases the amount of liquid components in plastisol and can definitely reduce the viscosity, but the use of a large amount of diluent worsens the working environment and also poses the risk of ignition during heating during processing. This is not desirable because it involves In addition, the use of a thinning agent is generally effective in a small amount and is preferable, but it often affects the foaming processability and causes cells to burst during the foaming process, making it impossible to obtain a foam with the desired thickness. The smoothness of the surface is also impaired, making it easy to cause the so-called foam settling phenomenon, which occurs when the foam material is heated prior to embossing with an embossing roll (hereinafter referred to as reheating settling). ).

Therefore, when trying to reduce the viscosity of plastisol, a thinner is not only effective in reducing viscosity, but also in improving processability.

It was necessary to carefully consider the effect on product characteristics when making a selection. In addition, it is of course effective to add a thinning agent together with other compounding agents when preparing plastisol, but it is recommended to include it in advance in the paste PVC in order to avoid the hassle of measuring operations during compounding. is desired.

[Problem that the invention seeks to solve]

As a result of extensive research into a method for obtaining a paste PVC that provides plastisol with low viscosity and excellent foam processing suitability without adversely affecting product quality, the present inventors found that a plurality of nonionic surfactants with a specific structure were used. The inventors have completed the present invention by discovering that by adding a combination of agents to a polymer latex, a PVC paste can be obtained that provides plastisol with a low viscosity without impairing foaming processability.

[Means for solving problems]

In the present invention, when producing a polyvinyl chloride resin for paste processing by spray-drying a vinyl chloride polymer latex obtained by polymerizing vinyl chloride, the following two A and two B are added to the polymer latex after the completion of polymerization. The compound represented by 2 B is added to the resin in such a manner that the weight ratio of the compound represented by 2 B to the compound represented by 2 A is 1 or less, and the amount of the compound represented by 2 B added is 0.05% by weight or more of the resin α5 A method for producing a polyvinyl chloride resin for paste processing, characterized in that the amount of the polyvinyl chloride resin added is less than % by weight.

The plastisol viscosity-reducing additive (hereinafter referred to as a thinner) used in the present invention consists of two types of components with different structures, one of which is a sorbitan ester represented by the following formula A.

X In the formula, R is an alkyl group or alkenyl group having 12 to 18 carbon atoms, and X is a polyoxyethylene group (+cHt・C
H, 0% H) or an acyl group (-C-R).

Moreover, n is an integer of 4-20.

Examples of such compounds include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monoolex-), sorbitan trioleate, nrubitan sesquioleate, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan monolaurate. There are ethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan polyoleate, etc., but those with polyoxyethylene chains are preferable in terms of viscosity reducing effect. .

The other one is polyoxyethylene alkyl (or alkenyl) phenyl ethers represented by the following formula B.

B: In the formula, R is an alkyl group having 8 or 9 carbon atoms.

Moreover, n is an integer of 4-20.

Both of the compounds represented by A and B are generally known as thinning agents for paste PVC, but the effects of the present invention cannot be obtained when each is used alone. In other words, although the compound added to the second layer does not have a negative effect on the foaming processability, the viscosity-reducing effect is not sufficient. Even if the amount added is increased, the viscosity-reducing effect cannot be obtained. On the other hand, the compound of formula B has a large viscosity-reducing effect, and as the amount added increases, the viscosity-reducing effect is also observed over a wider range, and exhibits favorable behavior as a viscosity-reducing agent. It becomes easy to cause settling when reheating.

However, when these two compounds are used in combination in a certain ratio, a sufficient viscosity-reducing effect can be obtained without any adverse effects such as stagnation upon reheating. Such an effect has not been known so far, and was discovered for the first time through studies by the present inventors. In the present invention, the compound (I) represented by 2A and the compound (II) represented by 2B are used in a range in which the weight ratio of ■ to ■ does not exceed 1, and the amount of ■ added to the paste PVC. 0.05 against
It is used within a range of % by weight or more and less than α5 weight.

If the weight ratio of H to I exceeds 1, stickiness during the foaming process, especially reheating, will tend to occur, and if the weight of H is 0.5% by weight or more based on the paste PVC, it may not be used in combination with I. The effect of suppressing the settling phenomenon can no longer be obtained, and on the other hand, the effect of lowering the sol viscosity cannot be sufficiently exhibited if the α content is less than 5% by weight. These compounds are added to the polymer latex after the polymerization is completed during the production of PVC paste. It is not preferable to add it before polymerization or during polymerization, when the polymerization has not progressed sufficiently, because it usually affects the polymerization behavior and the properties of the obtained polymer latex. Since the same effect can be obtained by adding it to the polymer latex either before or after recovering the unreacted monomer, the method convenient for operation can be selected.

〔Example〕

The present invention will be explained below with reference to Examples.

Manufacturing side of paste PVC used in the present invention Polyvinyl chloride particles containing an oil-soluble polymerization initiator and polyvinyl chloride containing no polymerization initiator are used as seed particles, and a surfactant whose main component is alkyl sulfate ester soda salt is used. The seeded microsuspension polymerization of vinyl chloride was carried out using the agent as an emulsifier. After collecting the unreacted upper layer, the resulting polymer latex was dried in a spray dryer, and then pulverized to obtain a polyvinyl chloride resin for paste processing (Resin A).

Example 1 Polyoxyethylene sorbitan monolaurate (trade name: Rheodol TWL106, manufactured by Kao Seiken) was added to a polymer latex obtained by polymerizing vinyl chloride and recovering unreacted monomers in the same manner as shown in the production example of paste PVC. 0.0% based on the weight of vinyl chloride polymer contained in the latex.
Polyoxyethylene octylphenyl ether (trade name Emuldan 810:
2 weights of VCa (manufactured by Kao) were added thereto, stirred for a while to disperse and dissolve, and then sprayed, dried and crushed in the same manner as in the case of Resin A to obtain a paste PVC. (Resin B) These resins were kneaded in the following formulation to prepare plastisol for foam processing.

Paste PVC 100 parts by weight Plasticizer (DOP).

Calcium carbonate 135 Foaming agent 6 Stabilizer 3 Pigment (Tto, ) 1s Diluent 5 The viscosity of these plastisols was measured using a BBH type rotational viscometer (Tokyo Keikimei Co., Ltd.) at 60-tar and 20 rpm, and it was found that Resin A The viscosity of plastisol using is k
It was OOpoise. On the other hand, the viscosity of the plastisol of Resin B was 68 poiθe.

These plastisols were applied thinly onto flame-retardant paper using a doctor knife and heated at 200° C. for 10 seconds to prepare a semi-gel sheet. The thickness of the coating layer after semi-gelling is
[It was 122M. Next, it was heated at 200° C. for 6 a second to foam. The foam sheet was left to cool for 1 hour in a constant temperature room at 25° C. with a humidity of 55° ± 3°, and then heated again in an oven at 200° C. for 30 seconds.

The thickness of the foam sheet before and after reheating was measured, and the ratio (L/lo) of the thickness (a) after reheating to the thickness (a) before reheating was determined. So it was 1.05. On the other hand, the foam sheet using resin B had a value of 1.05. That is, when Resin B was used as opposed to the control side using Resin A, no settling phenomenon due to reheating was observed, and a good foaming state was maintained.

Example 2 The same procedure as in Example 1 was repeated except that the amounts of polyoxyethylene sorbitan monolaurate and polyoxyethylene octylphenyl ether were changed to 1.5% by weight and 1% by weight, respectively. A sticky agent-containing paste PVC was prepared and the plastisol viscosity and thickness ratio before and after reheating were measured under the same conditions as in Example 1. The plastisol viscosity was 54 poise thickness ratio C1/lo
> was 1.06.

Comparative Examples 1 to 3 Using only polyoxyethylene octylphenyl ether as an additive and changing the amount added to 03% by weight and 1.0% by weight, paste PVC was prepared in the same manner as in Example 1. When the plastisol viscosity and thickness ratio before and after reheating were determined under the same conditions as in , they were 75 poise, 80 poise, and 45 poise, respectively.
It was α45. On the other hand, in the case of paste PVC obtained by adding only 1.0% by weight of polyoxyethylene sorbitan monolaurate as an additive, 70 poise was obtained.
and 1.00.

Example 3 As an additive, polyoxyethylene sorbitan monooleate (trade name Rheodol TWL80: manufactured by Kao Soap)
a, S weight% and polyoxyethylene nonylphenyl ether (Emulgen?03,
A paste PVC was prepared using 12% by weight of (manufactured by Dani Atlas). The plastisol viscosity and thickness ratio before and after reheating, which were determined in the same manner as in Example 1, were each 70 poise.
and 1.0.

Comparative Example 4.5 A paste PVC was prepared in the same manner as in Example 1, except that the amounts of polyoxyethylene sorbitan monolaurate, polyoxyethylene octylphenyl ether, and polyoxyethylene octylphenyl ether were set to rl, 3% by weight, and 0.5% by weight, respectively. The plastisol viscosity and thickness ratio before and after reheating were determined to be 58.
Poise and Q were 60. In addition, the added amounts of polyoxyethylene sorbitan monolaurate and polyoxyethylene octylphenyl ether were each 1.0.
When the plastisol viscosity was set to 15% by weight, the viscosity of the plastisol was 57. Poisθ The thickness ratio (ν4) before and after reheating was 0.
It was 65.

Example 4 A paste PVC was prepared in the same manner as in the preparation of Resin B in Example 1, except that the amount of polyoxyethylene octylphenyl ether added was 0.055% by weight of the vinyl chloride polymer. When the plastisol viscosity and the thickness ratio before and after reheating were measured using this paste PVC in the same manner as in Example 1, the plastisol viscosity was 79 poiθe and the thickness ratio (t/1oX11.02).

Comparative Example 6 A paste PVC was prepared in the same manner as in the preparation of Resin B in Example 1, except that only polyoxyethylene sorbitan monolaurate was added as a thinner at 5% by weight based on the vinyl chloride polymer. Example 1 using this paste PVC
When the plastisol viscosity and thickness ratio before and after reheating were measured in the same manner as above, the plastisol viscosity was 83 pois.
e, thickness ratio (L/mu) was 1.03.

Comparative Example 7 Plastisol viscosity and plastisol viscosity before and after reheating were carried out in the same manner as Comparative Example 6 except that polyoxyethylene sorbitan monolaurate was added at α3% by weight and polyoxyethylene octylphenyl ether was added at α01% by weight based on the vinyl chloride polymer. The thickness ratio (t/lo) was measured. Sol viscosity is 83
Poise was 1.02.

Example 5 Example 5 except that polyoxyethylene sorbitan monolaurate and polyoxyethylene octylphenyl ether were added to the polymer latex after the completion of polymerization and before recovery of unreacted monomers, and then the unreacted monomers were recovered. A thinning agent-containing paste PVC was prepared in the same manner as in Example 1. The viscosity of plastisol determined in the same manner as in Example 1 was 67.
Poise.

The thickness ratio before and after reheating was 1.02.

Comparative Example 8 Except for adding 1.2 kg of polyoxyethylene sorbitan monolauryl ether (trade name: Rheotonil TWL106, manufactured by Kao Seiken) and polyoxyethylene octylphenyl ether (Emuldan 810, manufactured by Kao Atlas) CL8IC9 prior to the start of polymerization. Polymerization of vinyl chloride was carried out in the same manner as described in Example 1. Unreacted monomers were collected, then spray dried and pulverized to produce paste PVC. Plastisol was prepared according to the formulation described in Example 1, and the sol viscosity and thickness ratio before and after reheating were measured, and they were 65 poise and α58, respectively. Although the viscosity reduction effect was good, reheating A sagging phenomenon was observed.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain a paste PVC that provides a plastisol with low viscosity and excellent foaming processability.

Claims (3)

[Claims] (1) When producing a polyvinyl chloride resin for paste processing by spray-drying a vinyl chloride polymer latex obtained by polymerizing vinyl chloride, compounds represented by formulas A and B are added to the polymer latex to produce a polyvinyl chloride resin for paste processing. wherein the weight ratio of the compound represented by formula B to the compound represented by formula A is 1 or less,
and the amount of the compound represented by formula B added is 0.0 of the resin.
A method for producing a polyvinyl chloride resin for paste processing, which comprises adding the resin in an amount of 5% by weight or more and less than 0.5% by weight. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ R: Alkyl or alkenyl group of C_1_2 to C_1_8 etc. ▼ R: Alkyl group of C_8 to C_9 n: Integer from 4 to 20 (2) The manufacturing method according to claim 1, wherein the compounds represented by formulas A and B are added to the polymer latex after completion of polymerization and before recovery of unreacted monomers. (3) The manufacturing method according to claim 1, wherein the compounds represented by formulas A and B are added to the polymer latex after unreacted monomer recovery.