JPS58183737A - Surface-treated filler - Google Patents

Abstract

PURPOSE:To provide the titled filler capable of improving the moldability of a resin composition and reducing the temperature dependency of its flowability, and suitable as a modifier for synthetic resins and rubbers, by coating the surface of a filler with a hydroxyl-containing carboxylic acid ester. CONSTITUTION:The objective filler coated with a hydroxyl-containing carboxylic acid ester and optionally an unsaturated carboxylic acid, can be prepared by charging (A) a hydroxyl-containing carboxylic acid ester (preferably an unsaturated carboxylic acid lower hydroxyalkyl ester such as 2-hydroxyethyl methacrylate) and optionally 10-50wt% of an unsaturated carboxylic acid such as (meth) acrylic acid and (B) a filler such as ground limestone, etc. in e.g. a heat kneader, and mixing e.g. at 100-150 deg.C for 5-15min if necessary adding a lubricant, a radical generator, a pigment, and an antistatic agent to the mixture. EFFECT:The flow of the resin composition in the mold can be made uniform, and the molded product has little deformation and warpage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface-treated filler, and more particularly to a surface-treated filler having a specific coating formed on its surface.

Inorganic and/or bridged fillers improve the mechanical strength of synthetic resins such as polyolefins and polyvinyl chloride.

In addition to being used to improve thermal properties, paintability, and even moldability, inorganic fillers such as calcium carbonate and clay are widely used as components of paints, inks, and the like. For example, °calcium carbonate, magnesium carbonate, calcium sulfite, norium sulfate for the purpose of modifying polyolefins.

Fillers such as silica, talc, diatom, wood flour, and cellulose are used in papermaking, and the particles of these fillers are surface-treated and dispersed with a surface treatment agent such as an organic acid before being kneaded with the polyolefin. Improvements are being made in this area.

However, when a filler whose surface has been treated with an organic acid is blended with a polyolefin, it is easily discolored, causes 70-marks and warps on molded products, and has the disadvantage that the paintability is not sufficiently improved.

Therefore, the present inventors conducted repeated studies to develop a table + MJ treated filler that does not have such drawbacks, and as a result, they arrived at the present invention.
That's what I did.

The present invention relates to a surface-treated filler having a surface coated with a carboxylic acid ester having a hydroxyl group. Furthermore, the present invention relates to a surface-treated filler formed by forming a film of a sulfurcarboxylic acid ester having a hydroxyl group and an unsaturated carboxylic acid on the surface.

The filler used in the present invention is not particularly limited, and includes carbonates such as 0aOO, I Mg0O1, and BaOOB;
OaO, MgO, Bad, All0. , Ti
on, oxides such as ZnO; 0a(OH)1. Mg
(OH), , mu1(OH'), e ”a(01
Hydroxide such as 10m; 0a804, Mg80.
, sulfates such as Ba804; and various other substances such as silica, talc, clay, mica, glass fiber, metal fiber, wood powder, and cellulose.

These may be used alone, or two or more may be used in combination as a mixture. In addition, these fillers are usually α1
A size of about 10 μm is used.

The carboxylic acid ester having a hydroxyl group used to form a film on the surface of the filler is preferably a hydroxy lower alkyl ester of an unsaturated carboxylic acid. Specific examples of this ester include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl acrylate. Among these, 2-hydroxyethyl methacrylate-F
is particularly preferred. This carboxylic acid ester having a hydroxyl group may be used alone or in combination with an unsaturated carboxylic acid. An example of the unsaturated carboxylic acid used here is acrylic acid.

Examples include methacrylic acid. When unsaturated carboxylic acids are used in combination, they can be mixed in an amount of up to 50 parts by weight per 100 parts by weight of the ester, and usually 10 to 50 parts by weight per 1 part by weight of the ester. If the amount of unsaturated carboxylic acid exceeds 50 parts by weight, the whiteness and moldability may be poor when the resulting surface-treated filler is blended with a synthetic resin such as polyolefin. Note that if an unsaturated carboxylic acid is used within the above range, some dehydration reaction will occur! A very good surface treated filler is obtained.

When this surface-treated filler is blended with a synthetic resin such as polyolefin, the above-mentioned troubles are not caused, the moldability of the W resin composition is improved, and the mechanical strength of the molded article is improved.

Various methods can be used to form a coating (such as the above-mentioned carboxylic acid ester) on the filler.
A method of mixing at 0° C. for 5 to 15 minutes is preferred. In this case, other components such as a lubricant, a radical generator (organic peroxide, etc.), an antistatic agent, a heat stabilizer, etc. can be added as necessary.

For surface treatment of the filler, it is sufficient to coat the surface treatment agent such as the above-mentioned carboxylic acid varnish-yh to such an extent that a monomolecular layer is formed.
It is appropriate to use it in a proportion of 5 to 5 parts by weight, preferably 5 to 5 parts by weight.

When blending the surface-treated filler according to the present invention into synthetic resin such as polyolefin, the
It can be blended within a range of weight %. By blending the surface-treated filler of the present invention into a synthetic resin, surface treatment can be performed without surface treatment or by a known method. ! Mechanical properties and thermal properties can be improved in the same way as in the case of treated fillers.

Moreover, the moldability of the resulting resin composition is improved, particularly the temperature dependence is small, and the flow within the mold becomes uniform. Therefore, deformation and warpage of the molded product are small. Furthermore, the resulting molded product does not have 70-marks or discoloration.

Moreover, the paintability of the molded product is also good. Therefore, such molded products are useful as industrial materials for automobile parts, electrical equipment parts, and the like. The surface-treated filler of the present invention is useful not only for modifying synthetic resins but also as a plasticizer for rubbers. Further, among the fillers, calcium carbonate, clay, and the like can be further used as coating agents for paper, extender pigments for paints and inks, and the like.

Next, examples of the present invention will be shown.

Examples 1 to 8 100 overlapping parts of heavy calcium carbonate with an average particle diameter of t7μ and a specific surface of 1500 cd/l were placed in a Henschel mixer, heated to 150°C, and while stirring, 2-hydroxyethyl was added to the separation device 150. A filler whose surface has been treated by adding methacrylate alone or a mixture with acrylic acid in the proportions shown in Table 1 in the form of a mist using a spray device and mixing at normal pressure for 15 minutes (hereinafter referred to as surface-treated filler) ) was obtained.

The surface-treated filler is an ethylene-propylene block copolymer (melt index (iJ12t6ay).

Temperature 250°C) 8p710min, density αq floi
, trade name: J750H, manufactured by Idemitsu Petrochemical Co., Ltd.) in the proportions shown in Table 1. To 100 parts by weight of this mixture, 102 parts by weight of dicumyl peroxide and 12 parts by weight of stearic acid monoglyceride were added, and the mixture was stirred and mixed for 10 minutes at room temperature using a Henschel mixer.

Ta. Next, a predetermined amount of this mixture was wet kneaded for 5 minutes at a resin temperature of 230° C. using a bumper IJ mixer, and then formed into a sheet using a roll and pelletized using a sheet heretizer.

Injection molding +I using the resin composition thus obtained
A (manufactured by Niigata Iron Works, resin temperature 21 at 811 (So)
An ASTM standard test piece was prepared by molding at a temperature of 0°C and a mold temperature of 50°C. The physical properties of this test piece were measured 1 and the results are shown in Table 1. The measurement ability of each item is as follows.

Tensile properties: A8 TeM Bending properties by D-658: h
Izot impact performance with BTM D-790: A8T
Surface gloss according to MD-256: 8〒MD-52
Whiteness according to No. 5: Measured using a comparative method using a standard (Mgo) as 100% using a Thickett Kaken photoelectric colorimeter and a C-1 type proof filter.

Formability: Rice 150■, Width 200■, Depth 4o■, Wall thickness 2
The determination was made by measuring the pressure difference (△P) of the minimum light pressure when molding the glaze (2) at each molding temperature and mold temperature.

○... ΔP is small △... △P is slightly large ×... △P is large Foot→-N: Height 76so*, width 76■, wall thickness 5IIll
The determination was made by observing the flow state of the resin composition when molding the plate I. As for the 70-pattern, a uniform flow as shown in FIG. 1 was designated as pattern A, and a non-uniform flow as shown in FIG. 2 was designated as pattern B.

Molded product size: 150mm long, 200mm wide, 4 deep
It was determined by observing the degree of internal sillage when a box with a wall thickness of 0.0 cm and a wall thickness of 2.0 cm was molded.

Paintability: 5 at 120℃ after applying polyurethane resin paint.
After drying for 0 minutes, 100 1 square goblets were scratched on the coated surface with a sharp knife edge and peeled off using cellophane tape. In the table, A/100 indicates the number of remaining rough coating films.

Comparative Examples 1 to 5 Fillers without surface treatment or Table II used in the present invention
11 Using a filler whose surface has been treated with something other than a treatment agent 1
．． The same procedure as in Example 1 was carried out except for the following.

The results are shown in Table 1.

11 comparative examples 1 table

[Brief explanation of the drawing]

FIGS. 1 and 2 show row patterns during molding of the Fi resin composition. 1-・T-die, 2--Mold patent applicant Calp Industries Co., Ltd.

Claims (1)

[Scope of Claims] (II) A surface-treated filler formed by forming a film of a carmenic acid ester having a hydroxyl group on its surface. (2) The carbic acid ester having a hydroxyl group is a hydroxy lower alkyl ester of an unsaturated carbonic acid. A surface-treated filler according to claim 1. (3) A surface-treated filler formed by forming a film of carbic acid ester and unsaturated carmenic acid having hydroxyl groups on the surface. (4) A filler having hydroxyl groups. 4. The surface-treated filler according to claim 3, wherein the carbic acid ester is a droxy lower alkyl ester of an unsaturated carboxylic acid.