JPS60118709A - Chlorinated polyethylene composition - Google Patents

Abstract

PURPOSE:To provide the titled composition moldable by extrusion without causing foaming phenomenon, by compounding a chlorinated polyethylene with a specific amount of a hydrotalcite compound, a silane compound, a free radical generating agent, and a silanol condensation catalyst. CONSTITUTION:The objective composition can be produced by compounding (A) 100pts.wt. of a chlorinated polyethylene with (B) >=1pt.wt. of a hydrotalcite compound of formula (x is 10-20; y is 1-3; z is 10-20; w is 0-6) and (C) a silane of formula RR'SiY (R is olefinic unsaturated univalent hydrocarbon group or hydrocarbonoxy; Y is hydrolyzable organic group; R' is R or Y) (e.g. vinyl trimethoxysilane), a free radical generator (e.g. dicumyl peroxide), and a silanol condensation catalyst (e.g. dibutyltin laurate).

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND AND OBJECTS OF THE INVENTION The present invention relates to chlorinated polyethylene compositions.

Conventionally, chlorinated polyethylene and the general formula RR' S i Y
.

(In the formula, 1t is an olefinically unsaturated monovalent hydrocarbon group, which is still a hydrocarbonoxy group, Y is a hydrolyzable organic group, and W is a group R or a group Y.) A method of crosslinking by reacting silane (hereinafter simply referred to as silane) in the presence of a peroxide (free radical generator) and then exposing it to moisture in the presence of a silanol condensation catalyst is already known.

However, when the above-mentioned silane was reacted in the presence of peroxide and extrusion molded using a commonly used extruder, it was found that severe foaming occurred.

This is a phenomenon unique to chlorinated polyethylene that is not observed in ethylene copolymers such as polyethylene, and is a problem that is not practical.

An object of the present invention is to solve the above problems and provide a chlorinated polyethylene composition that does not cause foaming during extrusion molding.

[Summary of the invention]

In the present invention, based on 100 parts by weight of chlorinated polyethylene,
MgxA4y (OH)z CO, -WH20 (where x = 3 to 7. Y = 1 to 3. z = 10 to 20.
w, = 0 to 6), and further contains a silane represented by general 2RR'SiY, a free radical generator, and a silanol condensation catalyst. It is something to do.

In the present invention, various causes of the foaming phenomenon during extrusion molding were investigated, and as a result, it became clear that the main cause was hydrogen chloride produced by the reaction between the polymer and peroxide. Initially, attempts were made to suppress foaming by adding lead-based, tin-based, or epoxy-based stabilizers as hydrogen chloride scavengers, but even if hydrogen chloride was captured, foaming could not be suppressed. There wasn't. This is thought to be due to the time delay from generation to capture of hydrogen chloride.

Therefore, we investigated the foaming prevention effect during extrusion molding of various compounds that are thought to have the effect of suppressing the desorption of hydrogen chloride from chlorinated polyethylene and capturing and stabilizing the desorbed hydrogen chloride. , above, MgxAty(
It has been found that when a hydrotalcite compound represented by OH)zCO, -wH20 is mixed, the foaming phenomenon during extrusion molding can be completely suppressed. Chlorinated polyethylene 1
The reason why the lower limit of the amount of the hydrotalcite compound added to 00 it7:i[c was set at 1 part by weight is that foaming cannot be completely prevented below this value.

Although the upper limit is not particularly limited, it is preferably about 200 parts by weight from the viewpoint of processability, mechanical properties, etc.

The amount of chlorine in the chlorinated polyethylene used in the present invention varies depending on the required performance and processability, so it is not particularly limited. This is preferable because it maintains a balance between mechanical properties and mechanical properties.

In addition, the chlorinated polyethylene may include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, etc.
The ethylene-α olefin copolymer may be mixed depending on the purpose.

``Also, due to demands for processability, mechanical properties, etc., it is also recommended to add plasticizers such as 71-ruic acid esters such as DOP and trimellitic acid esters such as nTO'J'M.
The type and amount of the plasticizer to be mixed vary depending on the chlorinated polyethylene used and the purpose, and are not particularly limited.

In the general formula of the silane used in the present invention, It represents a monovalent olefinically unsaturated radical consisting of carbon, hydrogen and optionally oxygen. Examples of such radicals are vinyl, allyl, butenyl, cyclohexenyl, cyclopentadienyl, cyclohexadienyl, CLI, = C(CI, )COO(CH,), -
CI, = C< CIL)COOC1-LCI-L
O(CI-T2) h − and 0f( CI !2= C(CIL) Coo CI 1.CI
-f, QCH, CI C1,0(CH2)s -, and a vinyl radical is preferred. Y substituents include alkoxy-spanning alkoxy radicals with up to 6 carbon atoms, such as methoxy, ethoxy and butoxy radicals, and acyloxy radicals with up to 6 carbon atoms, such as pormyroxy, acetoxy or propiotsuki diradicals, and 14 Oxime radicals with up to 1 carbon atoms, e.g.
J(i Oyohi-0N=C(C, H), R' group is an aliphatic unsaturated monovalent hydrocarbon group,
For example, it can represent methyl, ethyl, propyl, tetradecyl, octadecyl, phenyl, benzyl, or tolyl. The R' group can also be represented by an R group or a Y group. Preferably, the silane has the formula R81Y and contains six hydrolyzable organic groups, with vinyltriethoxysilane and vinyltrimethoxysilane being most preferred. However, silanes with only two hydrolysable groups, such as vinylmethyldiethoxysilane and vinylphenyldimethoxysilane, are also effective.

The proportion of seven runs used depends in part on the reaction conditions and in part on the degree of modification desired in the chlorinated polyethylene. The actual proportions are, for example, 0 based on the weight of chlorinated polyethylene, or both chlorinated and non-chlorinated polyethylene (when the latter is present).
．． It can vary widely, such as from 1 to 20% by weight. However, in general, 0% based on the weight of chlorinated polyethylene
．． It is preferable to use a weight factor of 5 to 5.

As the free radical generator, any compound that can generate free radical sites in chlorinated polyethylene under the above reaction conditions and has a half-life of 6 minutes or less, preferably 1 minute or less even at the above reaction temperature. can be used.

Preferred radical-generating compounds for use in the present invention are organic peroxides and bersesters, such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-6-butyl peroxide,
, 5-dimethyl-2,5-di(peroxybenzoate)hexyne-6゜1,3-bis(t-butylperoxyisopropyl)benzene, lauroyl peroxide, 6-butylberacetate, 2,5-dimethyl -2・5-
di(phthylbaroxy)hexyne-3,2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 6-butylbarbenzoate, and azo compounds such as asobisisobutyronitrile and dimethylazo Diisobutyrate, most preferably dicumyl biroxide. The amount is 0 based on the weight of chlorinated polyethylene.
．． Preferably, it is used for weights of 1 to 1 weight.

Any of a wide variety of materials that act as silanol condensation catalysts can be used in the present invention. Such materials include, for example, titanium carboxylates such as dibutyltin dilaurate, stannous acetate, stannous octate, lead naphthinate, zinc oftate, iron-2-ethylhexoate, and cobalt naphthene-1. , X 7- /L.

and chelates, such as organometallic compounds such as tetrabutyl titanate, tetrabutyl titanate and bis(acetylacetonyl)diisopropyridanaate and organic bases such as ethylamine, hexylamine, dibutylamine and piperidine and mineral acids and fatty acids. acids such as. Preferred catalysts are organotin compounds such as dibutyltin dilaurate, dibutyltin diacetate and dibutyltin dioctate. The silanol condensation catalyst can be mixed before, during, or after the reaction of the chlorinated polyethylene and the silane.

〔Example〕

The present invention will be explained in detail below.

In the Examples and Comparative Examples shown in Table 2fλ1, compounding agents other than dicumyl peroxide and vinyltrimethoxysilane were used at a temperature of 150°C set at a temperature of 120°C to 160°C.
A sheet is prepared by kneading for 60 minutes using a rubber roll with a diameter of 100 yen. Next, this sheet was crushed using a crusher 1 at room temperature, impregnated with the dicumyl peroxide and vinyltrimethoxysilane in a closed system at 60°C, and the head and cylinder were heated to 180°C. A graft reaction is carried out using a 40-Yu extruder (L/J)-22), which is then shredded into pellets.

On the other hand, the ingredients shown in Table 2 are kneaded using rolls in the same manner as described above to prepare a sheet, and this sheet is made into a pellet-like material called a catalyst masterbatch of about 21 squares.

Then, this catalyst mask batch and the compositions listed on each side of Table 1 which were subjected to the graft reaction and shredded into pellets were mixed at a weight ratio of 1:19 and stirred. This was extruded using a 40 Dragon extruder with the head and cylinder set at a temperature of 170°C to a thickness of 211 mm and a width of 25 mm. The cross section of the tape was extruded into a tape shape, and the cross section of the tape was visually observed to see if there was any foaming. As a result, no foaming was observed in any of the examples.

Examples 1 to 4 are cases in which the composition and mixing amount of the hydrotalcite compounds MgxA4yOH2CO, .wH2Q, which are required by the present invention, were changed with respect to chlorinated polyethylene (chlorine content: 40%).

Example 5 uses chlorinated polyethylene with a small amount of chlorine, Example 6 uses chlorinated polyethylene mixed with ethylene-ethyl acrylate copolymer, and Examples 7 and 8 use a combustion aid, This is the case when compounding agents such as white fillers are added.

On the other hand, Comparative Examples 1 to 4 contain one or more stabilizers for general chlorinated polyethylene and do not contain any hydrotalcite compound.
The sample contained a hydrotalcite compound in an amount less than the specified amount according to the present invention, and foaming of Kana 9 was observed even in the case of collapse.

〔Effect of the invention〕

As explained above, the chlorinated polyethylene composition of the present invention has excellent industrial utility value since no foaming phenomenon occurs in the molded composition during extrusion molding.

Claims (1)

[Claims] 1. Mgx for 100 parts by weight of chlorinated polyethylene
Aty (OH)zcOm-wI-1,O(TadamuX-
10-20, y=1-3. z=10-20. w=0~6
) containing 1 part by weight or more of a hydrotalcite compound represented by is a hydrolyzable organic group, and R' is a group R or a group Y), a free radical generator, and a silanol condensation catalyst. .