DD250635A3 - Wax masses for signing and crayons - Google Patents

Abstract

The invention relates to wax compositions for the production of painting and marking pens for different surfaces. To improve the fracture stability and the use properties and the processability of the composition, this consists of 15-50% by weight of an ethylene-vinyl ester copolymer 20-40% by weight of a paraffin with freezing point 320-324 K 5-20% by weight of a polyethylene wax and 5-35% by weight of a dye or extender pigment. Particularly, the ethylene-vinyl ester copolymer has been found to be an ethylene-vinyl acetate copolymer.

Description

Field of application of the invention

The invention relates to wax compositions for the production of shaped bodies, preferably in stick form, which are suitable for writing or painting on documents such as paper, metal, plastic, glass, wood or leather.

Characteristic of the known technical solutions

Crayons compositions require many components or additives to meet the utility value-setting criteria set for them.

On the one hand, the finished product made from it should be uniform and solid, but also tough and rigid to form an acceptable support structure, on the other hand, the mass must still be soft enough to rubbing under pressure a writing or Malspur against the signed or leave the surface to be painted. In addition, the mass should have a good processability and be resistant to delamination or lumps during the physical marking or writing process.

Wax sticks which are essentially made of fat-soluble inorganic or organic pigments, where appropriate, are generally known.

Blends with fillers and binders from paraffins and waxes (Römps Chemie-Lexikon, 7th edition, 3858) and, if necessary

other additives, such. B. stearic acid or derivatives thereof (DD-PS 3205) exist.

As a waxy component substances of very different origin are used, such. As natural waxes such as Japan, carnauba or beeswax, microcrystalline petroleum waxes or synthetic hydrocarbon waxes such. B.

Polyethylene waxes (DE-OS 1778095) or unsaturated a-olefins (US-PS 3772233).

However, the wax sticks made from these compositions do not fully meet the demands placed on them. On the one hand, they have an unsatisfactory shape and fracture stability and / or color in the hand, so that they are often replaced by additional, uneconomical measures, such. B. by wrapping with a paper protective sleeve, must be stabilized. On the other hand, they give off unevenly the color body, so that a "crumbly", interrupted Malspur results, or they tend to heat or sunlight exposure to crosslinking, whereby the pin embrittles.

The breaking strength of the wax pencils can be significantly increased if the compositions high molecular weight polyolefins added (DE-OS 2613933, DE-AS 1519933, US-PS 3933708). However, the mass loses its softness, so that a higher pressure when signing or painting must be spent in order to produce a color track can. Such pens are unsuitable for painting for children.

At higher polyolefin content also the addition of a plasticizer and / or emulsifier (DE-OS 2843806) is inevitable to produce a recognizable, adhesive Malspur on smooth surfaces. A further disadvantage of all polyolefin wax crayons is that the homogenization and deformation of the compositions necessitates numerous machines and devices due to the high melting ranges of the polyolefins and the poor compatibility with the other components.

The mixture must be intensively homogenized at elevated temperatures and, if possible, is then first processed into granules before the mass of the spray press or the like is fed in, in order to avoid settling of the polyolefin constituents for longer service lives.

Object of the invention

The aim of the invention is to increase the breaking strength, to improve the performance properties and to simplify the processability of the composition, by changing the wax mass in the marking and coloring pencils.

Explanation of the essence of the invention

The invention has the object to develop a wax composition with sufficient resistance to breakage and dimensional stability, the components have low melting ranges and high compatibility with each other and have a corresponding softness, the light pressure a well visible, color intensive, closed, well on smooth surfaces well-adherent Malspur leaves. At the same time, it should be possible to process the compound into sticks simply from the melt. This object is achieved by a wax composition, which is composed according to the invention

From 15 to 50% by weight of a copolymer of ethylene with 20 to 40% by weight of a vinyl ester or vinyl acetate, a number average molecular weight of 2,000 to 6,000 and a molecular nonuniformity of from 2.5 to 25,

20 to 40% by weight of a paraffin with a solidification point of 320 to 324 K,

From 5 to 20% by mass of a polyethylene wax having number-average molar masses of from 1000 to 5000 and a solidification point of from 370 to 378 K,

5 to 35 Ma .-% of a color pigment or a pigment blend.

According to the invention, particularly those waxy ethylene-vinyl acetate copolymers in combination with polyethylene waxes and hard paraffin having a number average molecular weight of 2,000 to 4,000, a vinyl acetate content of 25 to 35% by mass and a molecular nonuniformity (weight average: number average 1) of 3 have proved suitable to 8 have.

These ethylene-vinyl acetate copolymers are prepared by high-pressure polymerization according to DD-PS 159506 or 153488.

Due to the high molecular nonuniformity, the waxes contain both low molecular weight product proportions and sufficiently high molecular weight fractions, which in combination with the polyethylene wax and paraffin can form a sufficient support structure and give the pens a high impact and impact resistance, although the waxy ethylene-vinyl acetate copolymers Single component have a softer, slightly sticky consistency. The high content of ester moieties imparts polarity to the molecule, resulting in improved, uniform dispersion of the pigment and increasing the intensity of the color.

At the same time, the adhesive strength improves on smooth surfaces. A particular advantage of the wax composition of the invention is that very little formulation ingredients are required to give the end product both high fracture stability and good marking and painting ability. Neither dispersants nor other additives are necessary.

The invention will be explained in more detail with reference to the following examples.

embodiments

The characteristics used to characterize the synthetic waxes and paraffins are determined by the following methods:

Solidification point on the rotating thermometer (EP) according to TGL 0-51556,

Vinyl acetate content of the copolymer (Vac) by the saponification method,

- number average (M _n ) and weight average (M _w ) molecular weight determined by gel permeation chromatography,

- nonuniformity (U) U = - - 1

M _n

The quality of the pens is assessed in terms of surface texture, breakage stability and painting performance.

- To assess the resistance to breakage, an area of about 25 cm ^{2 is} filled with the pen without interrupting the painting process on drawing board. The pen must not break off. In each case 10 pins made from the recipe are tested.

- To evaluate the painting and signing behavior, five strokes of about 5 cm in length are applied side by side under moderate pressure on cardboard and on glass. Observations are made with regard to the uniformity of the application, the adhesive strength and smudge resistance as well as the color intensity.

example 1

Ingredients. Wt .-%

Waxy Eva copolymer fVac ^ i Ma .-%,

M _n: 2350, U: 3.5) 37

Hard paraffin (EP: 323 K) 30

PE wax (M _n : 2030, EP: 374 K) 20

- Color pigment (Wyralred) 13

For the production of wax crayons paraffin and waxes are melted in a stirred tank at 370 to 373 K and stirred. As soon as a clear mixture has formed, pigment addition takes place with stirring. Depending on its composition, the mixture can be further processed or heated to 380 to 390 K to improve the flowability, especially when using extender pigments. Die.Production of the pins is then either by casting or extrusion.

For properties that determine the usefulness, see Table 1.

Example 2

Ingredients Ma .-%

Waxy EVA copolymer (Vac: 27% by mass)

M _n: 3100, U: 7.2) 30

Hard paraffin (EP: 321 K) 30

PE wax (M _n : 1500, EP: 371 K) 5

- Pigment blend (mid-blue: 15% color pigment) 35

The processing of the wax mass and the production of the pins takes place analogously to Example 1. For the quality of the pins, see Table 1.

Example 3

Ingredients Ma-%

Waxy EVA copolymer (Vac 20.2% by mass, M _n 5 860, U = 25) 35

Hard paraffin (EP = 320 K) 40

PE wax (M _n = 1080, EP = 370 K) 19.2

- Color pigment 5.8

The processing of the wax mass and the production of the pins took place analogously to Example 1. For the quality of the pins, see Table 1.

Example 4

ingredients

Waxy EVA copolymer (Vac = 28.2% by mass, M _n = 4200, U = 18)

Hard paraffin (EP = 323 K)

PE wax (M _n = 3 150, EP = 376)

- Color pigment

Ma. -%

15 40 20 25

The processing of the wax mass and the production of the pins took place analogously to Example 1. For the quality of the pins, see Table 1.

Example 5

ingredients

Waxy EVA copolymer

(Vac = 39.8 mass%, M _n = 2 800, U = 2.5)

Hard paraffin (EP = 324 K)

PE wax (M _n = 4920, EP = 378)

- Color pigment

Wt .-%

50

20

25

The processing of the wax composition and the production of the pins was carried out analogously to Example 1.

For the quality of the pins, see Table 1.

Vergleichsbeispie!

The pins produced according to Recipe 1 and 5 are tested in comparison to commercially available marking pens. The results are

compared in Table 1.

The commercial marking pen is composed as follows:

Ingredients Ma .-%

- Zeresin1003 22,2

Hard paraffin (EP: 320 K) 30.5

- PE wax (M _n 1800, EP: 373 K) _ 14

- Color pigment red 13

- filler (chalk, kaolin) 20.3

Table 1

Rezepturl Recipe 2 Handelsübl. pen Surface texture smooth, non-porous surface, matt glossy, not rubbing off into the hand smooth, non-porous, glossy not discoloring porous, dull, rubbing off in the hand break resistance very good, no stabilization required very well 80% breakage, stabilization (eg paper protection sleeve) required

Qua itity of the sig nary and Malspur

closed, very good evenly, color intensive

adheres well to smooth, very good adhesion, good surfaces, sufficient smudge resistance smudge-proof

"Crumbly", flakes off in parts, poorly adhering to smooth surfaces, insufficiently smudge-proof

Continuation of Table 1

Recipe 3

Recipe 4 Recipe 5

Smooth, non-porous, shiny, smooth, non-porous, shiny,

texture non-staining non-staining

smooth, porenfrel ·, shiny non-staining

break resistance

very well

very good very good

Quality of the sign and trace

closed, very good even, color intensive

adheres well to smooth, very good adhesion, good surfaces, sufficient smudge resistance smudge-proof

closed, very good adhesion even on smooth surfaces, sufficiently smudge-proof

Claims (2)

1. wax compositions for signing and crayons of paraffins, waxes, dyes, ethylene-vinyl ester copolymers with 20 to 40% by weight of vinyl ester and optionally fillers, characterized in that the mass of From 15 to 50% by weight of the ethylene copolymer having a number average molecular weight of 2,000 to 6,000 and a molecular nonuniformity of from 2.5 to 25, 20 to 40% by weight of a paraffin with a solidification point of 320 to 324 K, From 5 to 20% by weight of a polyethylene wax having number average molecular weights of from 1,000 to 5,000 and a solidification point of from 370 to 378K and - 5 to 35Ma .-% of a color pigment or a pigment blend exists. 2. wax compositions according to item 1, characterized in that the ethylene-vinyl ester copolymer of an ethylene-vinyl acetate copolymer and a number average molecular weight of 2000 to 4000 a vinyl acetate content of 25 to 35 wt .-% and a molecular nonuniformity of 5 to 8 consists.